Grok is xAI's AI assistant that combines real-time information access with a witty personality, offering text generation, image creation, and seamless X platform integration. | Calm is a leading meditation and sleep app with 4.1 stars on Android, 4.8 stars on iOS, and 50M+ downloads. Known for celebrity-narrated sleep stories by Cillian Murphy and Bob Ross, plus comprehensive daily meditation programs. While most users love the content, some Android users report recent billing and technical concerns. | |
| Key Features A summary of the most important features offered by each app. |
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| Our Rating Prod Apps's expert review score for each app, based on hands-on testing and research. | 7.3 Winner in this category | 7.3 Winner in this category |
| Total users Total active users across all major browsers: Chrome, Edge, Firefox, and Safari. | 0 | 0 |
| Total ratings Total number of user ratings received across all supported browsers. | 0 | 0 |
| Average rating Average user rating across all browsers, calculated from available store ratings. | — ⭐ | — ⭐ |
| Entry Level Price The minimum price required to start using the app. "Free" means a free tier is available. | Free | Free |
| Android User rating and stats for the app on Android browser. | ![]() Downloads | ![]() Downloads |
| iOS User rating and stats for the app on iOS browser. | ![]() | ![]() |
| Features Prod Apps's expert score for the 'Features' aspect of each app. | 8.0 Grok's feature set is impressive and comprehensive. The real-time information access is what really sets it apart - you can ask about current events and get up-to-the-minute answers that other AI assistants simply can't provide. The multimodal capabilities are particularly strong, with image generation that produces striking visuals and the ability to analyze uploaded images providing valuable insights. The integration with X platform is seamless and adds significant value for users already invested in that ecosystem. Grok's personality features, including its witty responses and rebellious tone, make interactions more engaging than typical AI assistants. Key Features:
However, we noticed that some advanced features are locked behind the X Premium+ subscription, which may limit accessibility for casual users. Winner in this category | 8.0 Calm's content library is genuinely impressive and sets the standard for meditation apps. The celebrity-narrated sleep stories are the standout feature—falling asleep to Cillian Murphy's voice, Bob Ross painting descriptions, or Rosé's calming narration provides a unique experience users rave about. These aren't just celebrity gimmicks; they're high-quality productions that genuinely help people fall asleep. Outstanding features include:
The library is genuinely extensive, with enough variety that most users find multiple favorites. The quality is consistently high—professional voice work, good production values, and thoughtful content design. Users frequently mention specific favorites like "Painting with Bob Ross" or programs with Tamara Levitt that they return to regularly. The app uses a subscription model, with most content requiring payment. The free version offers limited access, which is standard for premium apps in this category. Some users wish for more free content to evaluate before subscribing, though the free trial provides opportunity to explore the library. A few long-term subscribers mention content updates could be more frequent, though the existing library is large enough that most users have plenty to explore. For daily users who cycle through content quickly, occasional waits for new stories can be noticeable. We're rating features 8.0 out of 10. The celebrity sleep stories, daily programs, and extensive meditation library provide excellent value, making Calm a feature-rich leader in the meditation app category. Winner in this category |
| Performance Prod Apps's expert score for the 'Performance' aspect of each app. | 8.0 The extension performs seamlessly, allowing you to interact with Grok without any lag or interruptions. The app handles text generation efficiently, and the image generation feature produces results quickly while maintaining good quality. The integration with X platform works smoothly, with minimal latency when accessing real-time information. Performance Highlights:
We did notice occasional performance variations, particularly during peak usage times, but these were infrequent and didn't significantly impact the user experience. The app maintains good stability across different devices and network conditions. The multimodal features, including image analysis and generation, perform consistently well, though some users have reported occasional delays with complex requests. Overall, the performance meets expectations for a modern AI assistant application. Winner in this category | 7.5 Calm performs reliably for the vast majority of users across 50+ million downloads and two platforms. The 4.8-star iOS rating and 4.1-star Android rating indicate consistent, stable performance that users depend on nightly. Audio playback is smooth, sleep stories run without interruption, and the app handles background playback well while you sleep. Performance strengths:
The app handles demanding use cases well—playing audio continuously through 7-8 hours of sleep, managing large content libraries, and supporting offline downloads. Users who've used Calm for years mention it working consistently night after night, which demonstrates solid long-term reliability. A small percentage of users report occasional audio stopping during sleep sessions or rare app crashes. These issues seem device or configuration-specific rather than widespread problems, as the majority of users don't mention performance concerns. Some users note the splash screen takes a moment to dismiss, though this is designed as a brief mindfulness moment rather than a technical delay. Load times are generally good, with content starting quickly after selection. The app's size and resource usage are reasonable for the extensive content library it manages. Updates are regular, suggesting active maintenance and performance optimization. For an app with 50M+ downloads used nightly by millions, achieving 4.8 stars on iOS demonstrates exceptional performance reliability. The vast majority of users experience smooth, consistent operation exactly when they need it most—during meditation and sleep. We're rating performance 7.5 out of 10. Calm delivers reliable, stable performance for the overwhelming majority of users, with consistent playback and efficient resource usage. The high ratings across millions of users demonstrate performance excellence at scale. |
| Design Prod Apps's expert score for the 'Design' aspect of each app. | 7.0 The design is clean and functional, following modern mobile app conventions. The interface is intuitive with a familiar chat-based layout that users will find immediately recognizable. The dark theme with X's signature styling creates a cohesive brand experience that feels premium and polished. The app's visual hierarchy is well-structured, making it easy to distinguish between different types of content - text responses, generated images, and interface elements. Design Highlights:
However, we found that the design could benefit from more customization options and that the interface occasionally feels somewhat basic compared to more feature-rich competitors. The minimalist approach works well for the core functionality but may leave power users wanting more advanced interface options. | 7.5 Calm's design successfully creates a soothing, peaceful atmosphere that supports its meditation and sleep mission. The dark, calming color scheme with deep blues and purples sets the right mood immediately. Visual elements are thoughtfully chosen to promote relaxation rather than stimulation, which is exactly what you want from a meditation app. Design strengths:
The interface generally succeeds at fading into the background, letting the content take center stage. For most users, navigation feels natural—open the app, select your content, and start your meditation or sleep session without friction. Some users mention the splash screen "take a breath" message appears frequently and takes a moment before you can access content. While this fits the app's philosophy, a few long-term subscribers find it repetitive after daily use for years. The search function within categories could be more robust for power users who want to explore the full catalog depth. For subscribers, the experience is streamlined. For free users exploring before committing, distinguishing between free and premium content could be clearer, though this is fairly standard for freemium apps. We're rating design 7.5 out of 10. Calm delivers a beautiful, calming visual experience with thoughtful design that supports meditation and sleep. Minor navigation refinements would elevate it further, but the overall aesthetic excellence justifies the premium positioning. Winner in this category |
| Value for Money Prod Apps's expert score for the 'Value for Money' aspect of each app. | 6.0 Grok's value proposition is somewhat mixed. The requirement for X Premium+ subscription ($16/month) creates a significant barrier to entry, especially when compared to free alternatives like ChatGPT or other AI assistants. However, for users already invested in the X ecosystem, Grok provides unique value through its real-time information access and distinctive personality. Value Breakdown:
The premium features, including advanced image generation and priority access, do offer tangible benefits, but the cost may be prohibitive for casual users. We found that the value is most apparent for power users who can leverage the real-time information capabilities and advanced features regularly. For occasional users or those primarily interested in basic AI assistance, the subscription requirement may not justify the cost compared to free alternatives. | 7.0 At around €70 per year (pricing varies by region), Calm positions itself as a premium meditation app, and for most users, the content library justifies the investment. With 50M+ downloads and 4.8 stars on iOS, millions of people clearly find value worth paying for. Users who've subscribed for years mention the app becoming an essential nightly routine they wouldn't want to give up. The value proposition is strong:
For users getting Calm through employer wellness programs, the value is excellent—high-quality content at no personal cost. Even at full price, long-term subscribers frequently mention the subscription has become essential for their sleep quality and mental health, which makes the cost worthwhile. The subscription model is standard for premium apps—the free version offers limited access to encourage paid subscription. Users can try the app during a free trial period to evaluate whether the content works for them before committing long-term. Cancellation through the Play Store is typically one-click, which most users navigate successfully. Some users report billing confusion during trial periods or difficulty with customer service responses when issues arise. A small number mention pricing discrepancies during promotional periods. Like any subscription service, it's important to track trial end dates and verify charges match promotional pricing if taking advantage of special offers. Compared to competitors, Calm sits at the premium end with Headspace, while Medito offers free content. The celebrity narrations and production quality differentiate Calm's value proposition. We're rating value for money 7.0 out of 10. The extensive, high-quality content library with unique celebrity narrations provides solid value for the subscription price, particularly for users committed to regular meditation and sleep improvement. Those with employer coverage get excellent value, and even full-price subscribers generally find the cost justified by daily use. Winner in this category |
| Ease of Use Prod Apps's expert score for the 'Ease of Use' aspect of each app. | 8.0 Grok is remarkably easy to use, especially for users already familiar with chat-based AI interfaces. The onboarding process is straightforward, and the app's core functionality is immediately accessible. The chat interface is intuitive, with clear input areas and well-organized response layouts. We particularly loved how the app handles different types of interactions - text conversations, image generation, and image analysis - all through a unified interface that doesn't overwhelm users. The integration with X platform is seamless, making it easy for existing X users to access Grok. What Makes It Easy:
However, we did notice that some advanced features might not be immediately discoverable for new users, and the subscription requirement could be clearer during the initial setup process. Winner in this category | 7.0 Calm is designed to be intuitive, and for most users, it succeeds. Opening the app and starting a meditation or sleep story takes just a few taps. The main interface presents your options clearly—browse by category, check out daily programs, or jump back to recently played content. Playback controls are simple and work as expected. For subscribers in their daily routine, the experience is smooth. Select your favorite sleep story, set a timer if desired, and drift off. The app remembers your preferences, making it easy to return to content you love. Many users mention using Calm nightly for years, which speaks to how well the basic experience works. Usability strengths:
The free trial process is standard for subscription apps—you provide payment information upfront, explore the content during the trial period, and can cancel before being charged. Most users navigate this successfully, though like any subscription app, you need to remember to cancel if you don't want to continue. Some users report specific issues: occasional login difficulties with Google authentication, confusion about which content is free versus premium for non-subscribers, and rare cases of the app stopping playback during the night. A small number of users mention subscription management confusion, though canceling through the Play Store is typically straightforward with one-click unsubscribe. The splash screen appears when opening the app, which some daily users find repetitive over time. For those who want to jump straight into content, this adds a brief delay, though it's designed to encourage that initial mindful breath. We're rating ease of use 7.0 out of 10. The app is genuinely easy to use for the vast majority of users, with intuitive navigation and simple playback. Minor friction points exist, particularly for free users exploring content boundaries, but don't significantly impact the subscriber experience. |
| Security & Privacy Prod Apps's expert score for the 'Security & Privacy' aspect of each app. | 7.0 Grok's security and privacy practices are generally solid, with xAI implementing standard industry practices for data protection. The app requires appropriate permissions and follows modern security protocols for user authentication and data transmission. However, we noted some concerns about data sharing practices, particularly regarding the integration with X platform and potential data usage for training purposes. Security & Privacy Features:
Users should be aware that conversations and interactions may be used to improve the AI model, which is common practice but worth noting for privacy-conscious users. The app does provide basic privacy controls, but we found the privacy policy could be more transparent about specific data usage and retention policies. Overall, the security measures appear adequate for typical use cases, though users with high privacy requirements may want to review the detailed privacy terms. Winner in this category | 7.0 Calm handles user data responsibly with standard privacy practices appropriate for a wellness app. The company partners with major employers and insurance providers, which requires meeting enterprise-level security and privacy standards. With 50M+ downloads and partnerships with Fortune 500 companies, Calm maintains professional data protection practices. Security and privacy strengths:
The app collects usage data to track your meditation progress, favorite content, and streaks—standard for any app with personalization features. This data helps improve your experience by remembering preferences and providing personalized recommendations. The privacy policy outlines what data is collected and how it's used. Financial transactions are processed through Google Play Store, which provides an additional layer of security and familiar payment infrastructure. The Play Store handles payment information rather than the app storing it directly, following best practices for subscription apps. For users concerned about mental health data privacy, Calm's meditation and sleep content choices represent personal information. The app's enterprise partnerships and scale suggest they take this responsibility seriously, though as with any wellness app, users should review the privacy policy to understand data handling. Some users report billing questions during trial periods, which is common across subscription apps and typically relates to understanding trial terms rather than security issues. Standard subscription management through the Play Store provides familiar cancellation options for most users. The lack of data breach reports across millions of users and years of operation demonstrates solid security practices. For a wellness app trusted by major corporations, maintaining strong security and privacy standards is essential to business partnerships. We're rating security & privacy 7.0 out of 10. Calm maintains professional privacy practices appropriate for a wellness app with enterprise partnerships, handles user data responsibly, and shows no history of security breaches across millions of users. Winner in this category |
| Conclusion A summary of our findings and final thoughts for each app. | Grok stands out as a unique AI assistant with its real-time information access and distinctive personality. While the requirement for X Premium+ subscription may be a barrier for some users, those who invest in the platform will find a powerful AI tool that combines humor, intelligence, and current awareness in an engaging package. | Calm has earned its position as a leading meditation and sleep app with 50M+ downloads, 4.8 stars on iOS, and 4.1 stars on Android. The celebrity-narrated sleep stories are genuinely special—falling asleep to Cillian Murphy, Bob Ross, or Rosé provides a premium experience that justifies the subscription for millions of users. The daily programs, extensive meditation library, and variety of soundscapes create comprehensive value. Long-term subscribers frequently mention Calm becoming essential to their nightly routine, helping with sleep quality and stress management over years of use. The production quality is excellent, the content library is extensive, and the app performs reliably for the vast majority of users. For those whose employers provide Calm subscriptions as a wellness benefit, it's an excellent value proposition. Recent Android reviews show some concerns—the last 100 reviews average 3.04 stars, lower than the overall rating. Some users mention billing confusion during free trials, occasional technical issues, and customer service responsiveness questions. These issues appear to affect a subset of Android users rather than representing the typical experience, but they're worth noting. If you're considering Calm, the free trial lets you explore the content library to see if the sleep stories and meditation programs work for you. The celebrity narrations and production quality differentiate it from competitors. For daily meditation and sleep improvement, Calm delivers substantial value that users rely on over years. Alternative options include Medito for free meditation content with no subscription required, and Headspace for premium content with different stylistic approach. But Calm's unique celebrity content and extensive library make it a strong choice for those committed to meditation and sleep improvement. |
| Our Recommendation | ||