scrum poker online

In the world of Agile project management, accurate estimation is crucial for successful project delivery. Scrum Poker, also known as Planning Poker, is a popular technique used by Agile teams to estimate the complexity of tasks. With the advent of remote work and distributed teams, Scrum Poker Online tools have become indispensable. This article explores the benefits, features, and best practices of using Scrum Poker Online for Agile estimation. What is Scrum Poker? Scrum Poker is a consensus-based technique used to estimate the effort required for tasks in Agile projects.

Ad Disclosure

ALLTop Rated By UsersLatestPopular

Updated: -

• Cash King Palace
  new

  

  Royal Wins100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Lucky Ace Palace
  

  Luck&Luxury100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Starlight Betting Lounge
  

  Celestial Bet100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Spin Palace Casino
  

  Win Big Now100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Silver Fox Slots
  

  Elegance+Fun100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Golden Spin Casino
  

  Luxury Play100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Royal Fortune Gaming
  

  Opulence & Thrills100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Lucky Ace Casino
  

  Luck&Luxury100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Diamond Crown Casino
  

  Opulence & Fun100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more
• Victory Slots Resort
  

  Spin to Win100% / $1500

  Casino popularity:

  Collecting more data...

  Payment methods

  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 
  • 

  Play
  • Wagering: 35 x (b)
  • Withdrawal time: 1 days
  • Minimum deposit to casino: $30
  • Bonus max bet: $5
  • Established: 2024
  • Free Spins: 200

  • 1st Deposit Bonus:100% / $1500 + 200 Free Spins
  • Bonus code: FRUIT22nd Deposit Bonus:100% / $1500 + 75 Free Spins
  • Bonus code: FRUIT33rd Deposit Bonus:75% / $3000 + 75 Free Spins
  • Bonus code: FRUIT44th Deposit Bonus:50% / $4500 + 200 Free Spins

  • Leading selection of slots
  • VISA casino site
  • HD streaming casino games
  • Newly unveiled casino
  • Signup offer now available
  • Mr. Gamble special bonuses

  Get the full details

  

  
  Show more

scrum poker online

In the world of Agile project management, accurate estimation is crucial for successful project delivery. Scrum Poker, also known as Planning Poker, is a popular technique used by Agile teams to estimate the complexity of tasks. With the advent of remote work and distributed teams, Scrum Poker Online tools have become indispensable. This article explores the benefits, features, and best practices of using Scrum Poker Online for Agile estimation.

What is Scrum Poker?

Scrum Poker is a consensus-based technique used to estimate the effort required for tasks in Agile projects. It involves team members assigning points to tasks based on their complexity, risk, and effort. The process is collaborative, ensuring that all team members contribute to the estimation process.

Key Steps in Scrum Poker

1. Task Selection: The Scrum Master or Product Owner presents a list of tasks that need to be estimated.
2. Card Distribution: Each team member receives a set of cards with point values (e.g., 0, 1, 2, 3, 5, 8, 13, 21, etc.).
3. Individual Estimation: Team members privately select a card that represents their estimate for the task.
4. Consensus Building: All cards are revealed simultaneously, and the team discusses any significant differences in estimates.
5. Re-estimation: If necessary, team members re-estimate the task until a consensus is reached.

Benefits of Scrum Poker Online

1. Remote Collaboration

Scrum Poker Online tools enable remote teams to participate in estimation sessions seamlessly. These tools often come with features like video conferencing, chat, and screen sharing, making it easy for distributed teams to collaborate.

2. Real-Time Estimation

Online Scrum Poker tools provide real-time estimation, allowing team members to see each other’s estimates instantly. This accelerates the estimation process and reduces the time spent on discussions.

3. Enhanced Transparency

Online tools often record estimation sessions, providing a transparent record of how estimates were derived. This transparency is beneficial for future reference and for understanding the rationale behind estimates.

4. Customizable Features

Many Scrum Poker Online tools offer customizable features, such as the ability to create custom card sets, set estimation scales, and integrate with other Agile tools (e.g., Jira, Trello).

Popular Scrum Poker Online Tools

1. Planning Poker Online

• Features: Real-time estimation, video conferencing, chat, and integration with Agile tools.
• Pros: User-friendly interface, customizable card sets, and robust collaboration features.
• Cons: Limited free version with advanced features requiring a subscription.

2. Scrum Poker for Jira

• Features: Integration with Jira, real-time estimation, and customizable card sets.
• Pros: Seamless integration with Jira, making it easy to estimate tasks directly from Jira issues.
• Cons: Requires a Jira subscription, and some features may be limited to premium plans.

3. Agile Poker

• Features: Real-time estimation, customizable card sets, and integration with Agile tools.
• Pros: Intuitive interface, robust collaboration features, and flexible pricing.
• Cons: Some advanced features may require a premium subscription.

Best Practices for Using Scrum Poker Online

1. Prepare the Tasks

Ensure that tasks are well-defined and understood by all team members before the estimation session. This helps in making accurate estimates.

2. Set Clear Ground Rules

Establish clear ground rules for the estimation session, such as time limits for discussions and the criteria for re-estimating tasks.

3. Encourage Participation

Ensure that all team members actively participate in the estimation process. Encourage open discussions and respect diverse opinions.

4. Use the Right Scale

Choose an appropriate estimation scale (e.g., Fibonacci sequence) that aligns with your team’s estimation practices.

5. Review and Reflect

After the estimation session, review the estimates and reflect on any discrepancies. Use this feedback to improve future estimation sessions.

Scrum Poker Online tools have revolutionized the way Agile teams estimate tasks, especially in remote and distributed environments. By leveraging these tools, teams can achieve more accurate and collaborative estimations, leading to better project outcomes. Whether you are a seasoned Agile practitioner or new to Scrum Poker, incorporating an online tool into your estimation process can significantly enhance your team’s productivity and effectiveness.

scrum poker cards online

In the world of Agile project management, estimation is a critical component of the Scrum process. Scrum Poker Cards, also known as Planning Poker, is a technique used to estimate the complexity and effort required for tasks. Traditionally, these estimations are done using physical cards, but with the advent of digital tools, online Scrum Poker Cards have become increasingly popular. This article explores the benefits and features of using online Scrum Poker Cards in Agile teams.

What are Scrum Poker Cards?

Scrum Poker Cards are a consensus-based technique used to estimate the effort required for tasks in Scrum projects. Each team member is given a set of cards with numbers representing story points or hours. The team discusses the task, and each member privately selects a card that represents their estimate. Once everyone has selected their card, the estimates are revealed, and the team discusses any significant differences.

Benefits of Using Online Scrum Poker Cards

1. Accessibility

• Remote Teams: Online Scrum Poker Cards allow remote teams to participate in estimation sessions without the need for physical cards.
• Anywhere, Anytime: Team members can join estimation sessions from anywhere, making it easier to accommodate different time zones and schedules.

2. Efficiency

• Quick Setup: Online tools often come with pre-configured decks and templates, reducing the time needed to set up estimation sessions.
• Real-Time Collaboration: Estimates are collected and displayed in real-time, facilitating quicker decision-making and reducing the time spent on discussions.

3. Enhanced Features

• Customizable Decks: Many online tools allow customization of card decks, including the option to add custom values or use different estimation scales.
• Historical Data: Online tools often store historical data, providing insights into past estimations and helping teams refine their estimation process over time.
• Integration with Other Tools: Online Scrum Poker Cards can be integrated with project management tools like Jira, Trello, and Asana, streamlining the workflow.

4. Transparency and Accountability

• Clear Records: Online tools keep a clear record of estimations, making it easier to track and review past decisions.
• Accountability: The digital nature of online tools ensures that all team members are held accountable for their estimates, promoting a culture of responsibility.

Popular Online Scrum Poker Tools

1. Scrum Poker Online

• Features: Real-time collaboration, customizable decks, historical data, and integration with popular project management tools.
• Pros: User-friendly interface, robust features, and reliable performance.
• Cons: Some advanced features may require a paid subscription.

2. Planning Poker by Agile Alliance

• Features: Simple setup, real-time estimation, and basic customization options.
• Pros: Free to use, easy to learn, and suitable for small teams.
• Cons: Limited advanced features and integrations.

3. Jira Agile Poker

• Features: Integration with Jira, real-time collaboration, and customizable decks.
• Pros: Seamless integration with Jira, robust features, and reliable performance.
• Cons: Requires a Jira subscription, and some features may be limited to premium plans.

How to Choose the Right Online Scrum Poker Tool

1. Team Size and Structure

• Small Teams: Tools like Planning Poker by Agile Alliance may suffice.
• Large Teams: Consider tools with robust features and real-time collaboration capabilities.

2. Integration Needs

• Existing Tools: If your team already uses project management tools like Jira or Trello, choose a tool that integrates seamlessly with them.
• Standalone Use: If you prefer a standalone tool, focus on features like customization and historical data.

3. Budget

• Free Options: Tools like Planning Poker by Agile Alliance offer basic features for free.
• Paid Options: Consider the cost-benefit ratio of paid tools, especially if they offer advanced features and integrations.

Online Scrum Poker Cards offer a modern and efficient way to conduct estimation sessions in Agile teams. With benefits like accessibility, efficiency, enhanced features, and transparency, these tools are becoming indispensable for Agile practitioners. By choosing the right online Scrum Poker tool, teams can streamline their estimation process, improve accuracy, and ultimately enhance their project outcomes.

scrum poker cards online

In the world of Agile project management, estimation is a critical component of the Scrum framework. One of the most effective tools for this purpose is Scrum Poker Cards. Traditionally, these cards are physical, but with the advent of digital tools, online Scrum Poker Cards have become increasingly popular. This article delves into the benefits, types, and best practices of using Scrum Poker Cards online.

What are Scrum Poker Cards?

Scrum Poker Cards, also known as Planning Poker, is a consensus-based technique used to estimate the effort required for tasks in Scrum projects. Each team member is given a set of cards with numbers representing story points or hours. The team discusses the task, and each member privately selects a card to represent their estimate. The estimates are then revealed simultaneously, and the team discusses any discrepancies before reaching a consensus.

Benefits of Using Online Scrum Poker Cards

1. Accessibility

• Remote Teams: Online Scrum Poker Cards allow remote teams to participate in estimation sessions without the need for physical cards.
• Anytime, Anywhere: Team members can access the tool from any location, making it convenient for global teams.

2. Efficiency

• Quick Setup: Online tools often have quick setup processes, reducing the time spent on preparation.
• Automated Features: Many online tools offer automated features like timer settings, automatic card reveal, and consensus detection.

3. Enhanced Collaboration

• Real-Time Interaction: Online platforms facilitate real-time interaction, making it easier for team members to discuss and refine their estimates.
• Historical Data: Some tools store historical data, allowing teams to track estimation trends and improve accuracy over time.

4. Cost-Effective

• No Physical Cards Needed: Eliminates the need for purchasing and maintaining physical cards.
• Subscription Models: Many online tools offer affordable subscription models, making them cost-effective for teams of all sizes.

Types of Online Scrum Poker Tools

1. Standalone Tools

• Planning Poker by Agile Alliance: A free, open-source tool that offers basic features for estimation.
• Scrum Poker Online: A simple, user-friendly tool that supports multiple teams and projects.

2. Integrated Tools

• Jira: Jira’s Agile project management software includes Planning Poker functionality within its platform.
• Trello: Trello offers add-ons like “Scrum for Trello” that integrate Planning Poker into their boards.

3. Customizable Tools

• Crisp: A customizable tool that allows teams to create their own estimation scales and rules.
• Scrumwise: Offers a flexible platform with customizable estimation options and integration with other tools.

Best Practices for Using Online Scrum Poker Cards

1. Choose the Right Tool

• Team Needs: Select a tool that aligns with your team’s specific needs and workflow.
• Ease of Use: Ensure the tool is user-friendly and requires minimal training.

2. Set Clear Rules

• Estimation Scale: Define the estimation scale (e.g., Fibonacci sequence) and ensure all team members understand it.
• Discussion Guidelines: Establish guidelines for how discussions should proceed to ensure efficient estimation sessions.

3. Facilitate Effective Discussions

• Encourage Participation: Ensure all team members actively participate in discussions.
• Address Discrepancies: Focus on addressing significant discrepancies in estimates to reach a consensus.

4. Use Historical Data

• Track Trends: Use historical data to identify trends and improve estimation accuracy over time.
• Adjust Estimates: Be willing to adjust estimates based on new information or changes in the project scope.

5. Regularly Review and Improve

• Post-Session Reviews: Conduct brief reviews after each session to discuss what went well and what could be improved.
• Continuous Improvement: Continuously seek ways to improve the estimation process and tool usage.

Online Scrum Poker Cards offer a modern, efficient, and cost-effective solution for Agile estimation. By leveraging the right tools and following best practices, teams can enhance their estimation accuracy and overall project success. Whether you’re managing a remote team or looking to streamline your estimation process, online Scrum Poker Cards are a valuable addition to your Agile toolkit.

agile planning poker online

Agile Planning Poker, also known as Scrum Poker, is a consensus-based technique used in Agile software development to estimate the effort required for tasks. It leverages the wisdom of the crowd to arrive at a more accurate estimation. With the advent of remote work and distributed teams, Agile Planning Poker has transitioned from physical cards to online platforms, making it more accessible and efficient.

What is Agile Planning Poker?

Agile Planning Poker is a method used to estimate the complexity, effort, or size of user stories, features, or tasks in Agile projects. It involves team members discussing the task and then privately selecting a card with a numeric value that represents their estimate. The cards are then revealed simultaneously, and the team discusses any discrepancies before reaching a consensus.

Key Components of Agile Planning Poker

• Estimation Scale: Common scales include Fibonacci (1, 2, 3, 5, 8, 13, 21, etc.) or T-shirt sizes (XS, S, M, L, XL).
• User Stories: The tasks or features to be estimated.
• Team Members: All stakeholders involved in the estimation process.
• Discussion: A collaborative discussion to understand the task better.
• Consensus: Agreement on the final estimate.

Benefits of Using Agile Planning Poker Online

1. Enhanced Accessibility

• Remote Teams: Online platforms allow teams to participate from anywhere in the world.
• Time Zone Flexibility: Participants can join at their convenience, reducing scheduling conflicts.

2. Improved Collaboration

• Real-Time Interaction: Online tools facilitate instant communication and feedback.
• Visual Aids: Platforms often include visual aids like charts and graphs to help in understanding the estimates.

3. Efficiency and Speed

• Automated Processes: Online tools automate the card selection and reveal process, speeding up the estimation.
• Data Tracking: Easily track and analyze past estimations for better future predictions.

4. Consistency and Transparency

• Uniform Estimation: Ensures that all team members use the same scale and methodology.
• Audit Trail: Keeps a record of discussions and decisions, promoting transparency.

Popular Online Agile Planning Poker Tools

1. PlanITPoker

• Features: Real-time collaboration, customizable decks, and integration with Agile tools like Jira.
• Pros: User-friendly interface, free version available.
• Cons: Limited advanced features in the free version.

2. Scrum Poker Online

• Features: Simple setup, anonymous voting, and exportable results.
• Pros: Easy to use, no registration required.
• Cons: Basic features, limited customization.

3. Agile Poker

• Features: Customizable decks, real-time chat, and integration with Slack.
• Pros: Robust features, good for large teams.
• Cons: Requires a paid subscription for advanced features.

4. Rally Software

• Features: Integration with CA Agile Central, customizable estimation scales.
• Pros: Deep integration with Agile tools, comprehensive features.
• Cons: Steep learning curve, higher cost.

Best Practices for Agile Planning Poker Online

1. Preparation

• Define User Stories: Clearly define the tasks to be estimated.
• Choose the Right Scale: Select an estimation scale that fits your team’s needs.

2. Conducting the Session

• Facilitator Role: Assign a facilitator to guide the session and ensure everyone participates.
• Discussion Time: Allow sufficient time for discussion before revealing the cards.

3. Post-Session

• Review and Reflect: Discuss the outcomes and identify any patterns or discrepancies.
• Continuous Improvement: Use the insights to refine future estimation sessions.

Agile Planning Poker Online has revolutionized the way Agile teams estimate and collaborate. By leveraging digital tools, teams can enhance accessibility, improve collaboration, and maintain consistency and transparency. Whether you are a seasoned Agile practitioner or new to the methodology, adopting an online Agile Planning Poker tool can significantly boost your team’s efficiency and accuracy in estimation.

Frequently Questions