Compare Merlin AI and Habit Diary: Which App is the Best?
Merlin AI combines ChatGPT, Grok AI, DeepSeek, Gemini, Claude, and Perplexity AI in one powerful app with 70+ AI tools. Enjoy 102 free daily queries and seamless cross-platform integration. | Habit Diary is a comprehensive habit tracking app that helps you build good habits through customizable tracking, 30-day challenges, and progress visualization. | |
| 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. | 8.3 Winner in this category | 7.2 |
| 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. | 9.0 Merlin AI has everything you'd want in an AI assistant. It brings together seven different AI models - ChatGPT, Grok AI, DeepSeek, Gemini, Claude, and Perplexity AI - all in one place. This means you don't need separate subscriptions for each one. We really liked the 70+ AI tools it comes with:
The best part is how easy it is to switch between different AI models - just one tap and you're using a different AI. Plus, everything syncs across your devices so you can start a conversation on your phone and continue it on your computer. Winner in this category | 7.0 Habit Diary offers a solid foundation of habit tracking features that cover the essential needs of most users. The app's core functionality includes customizable daily habits, progress tracking, and a unique 30-day challenge system that sets it apart from many competitors. What we found particularly effective during our testing:
However, there are some limitations that impact the overall feature score. The free version restricts the number of habits users can track, which several users found frustrating. Additionally, some advanced features like detailed analytics and custom widgets are locked behind the premium paywall. We also confirmed user reports that "the app does not appear to have any widgets" in the free version, and encountered the same Google backup problems that users report, with one user stating "i cant backup my account with google." Based on our testing and user feedback, we rate the features at 7.0 out of 10. The app delivers solid core functionality and some unique elements like the challenge system, but the freemium restrictions and limited free features prevent it from scoring higher. |
| Performance Prod Apps's expert score for the 'Performance' aspect of each app. | 8.0 The app runs smoothly without lag or interruptions when chatting with multiple AI models. The search function works quickly and accurately, so you can easily find your conversations. We tested it on different devices and platforms, and it performed well everywhere. The chat responses are fast, even when switching between different AI models. The cross-device sync works reliably, so you can start a conversation on your phone and pick it up later on your computer. The integration with Gmail and LinkedIn works well without delays. We did notice some occasional loading times when processing complex requests or large documents, but overall the performance is consistent and reliable for everyday use. The best part is that basic features work offline, so you can access your conversations even without an internet connection. Winner in this category | 6.5 Habit Diary performs exceptionally well in day-to-day use. The app is lightweight, launches quickly, and all interactions—such as marking completions, navigating between views, and customizing habits—are smooth and responsive. We encountered very few bugs or crashes, and the app remained stable even when tracking a large number of habits. User reviews echo this experience, with most people praising the app's reliability and speed. However, there are some performance considerations that impact our rating:
Overall, Habit Diary delivers a consistently fast and stable experience, both in our hands-on testing and according to the majority of user feedback. We rate its performance at 6.5 out of 10, acknowledging the app's solid technical foundation while noting that some premium features and external integrations could benefit from performance optimization. |
| Design Prod Apps's expert score for the 'Design' aspect of each app. | 8.0 The app looks clean and modern. It's easy to find what you need without getting lost in menus. The chat interface is well-designed with clear differences between responses from different AI models. We liked how the app works the same way whether you're on Android, iOS, or desktop. It adapts nicely to different screen sizes. The dark and light theme options are a nice touch, and you can customize the interface to your liking. The mobile version works really well too - you can easily access your AI conversations on your phone without any issues. | 8.5 Habit Diary presents a clean and modern design that prioritizes usability while maintaining visual appeal. The interface strikes a good balance between functionality and aesthetics, with a layout that makes navigation intuitive for most users. Design strengths we observed include:
However, there are some design aspects that could be improved. The free version's ad integration can feel intrusive and disrupt the otherwise clean aesthetic. Some users also noted that the widget functionality, while functional, could benefit from more customization options and better visual integration with the main app design. Overall, Habit Diary's design successfully creates an engaging and motivating environment for habit tracking. The interface effectively balances simplicity with functionality, making it accessible to users of all experience levels. We rate design at 8.5 out of 10, acknowledging the app's strong visual foundation while noting areas where the user experience could be further enhanced. Winner in this category |
| Value for Money Prod Apps's expert score for the 'Value for Money' aspect of each app. | 9.0 Merlin AI offers great value. You can use it for free without creating an account, and you get 102 queries per day across all the major AI models. This free access to ChatGPT, Grok AI, DeepSeek, Gemini, Claude, and Perplexity AI in one app saves you from needing multiple expensive subscriptions. The premium plan adds useful features like voice chat, advanced AI tools, and team collaboration. The pricing is reasonable, making it a good choice for students, professionals, and anyone who wants to boost their productivity. When we compared it to individual subscriptions for these AI services, Merlin AI saves you money while offering more convenience. You really can't find another tool that gives you this much value for so little cost. Winner in this category | 5.5 Habit Diary offers a freemium model with both free and premium features. The free version provides basic habit tracking functionality but comes with limitations on the number of habits you can track and some advanced features. Premium features include:
In-app purchases range from €7.49 to €28.99, with options for monthly, yearly, or lifetime subscriptions. The free version is ad-supported, which some users find intrusive, but it does provide enough functionality to evaluate whether the app fits your needs before upgrading. However, several factors limit the value for money. Users consistently mention that the free version restricts the number of habits they can track, which can be frustrating for serious users. The free version's ad-supported model creates a fragmented user experience that some users find off-putting. We rate value for money at 5.5 out of 10. While the app provides solid functionality and competitive pricing for premium users, the free version's limitations and ad-supported model create a mixed value proposition that may not appeal to all users. |
| Ease of Use Prod Apps's expert score for the 'Ease of Use' aspect of each app. | 9.0 Merlin AI is one of the easiest AI assistants we've tried. You can start using it right away without any complicated setup. The free tier gives you 102 queries per day, which is plenty to test everything out. Installing it is simple, and it works great on both Android and iOS. Switching between AI models is super easy - just tap to change from ChatGPT to Grok AI to Claude, and so on. The integration with Gmail and LinkedIn works smoothly. You don't need to configure anything complicated. The free tier lets you explore all the features without committing to anything, which makes it easy to learn at your own pace. We give it a 9 out of 10 because it's really user-friendly, though some of the more advanced features might take a bit of time to figure out. Winner in this category | 9.0 Habit Diary excels in user experience, with most users finding the app remarkably easy to navigate and use. The interface design prioritizes simplicity, making it accessible even for users who are new to habit tracking apps. Highlights include:
The only minor quirk is that some advanced features might benefit from more detailed onboarding or help documentation. Once learned, it's easy to use. Overall, Habit Diary's ease of use is one of its greatest strengths. The app successfully balances simplicity with functionality, making habit tracking accessible to a wide range of users. We rate ease of use at 9.0 out of 10, recognizing the app's excellent user experience while noting that some premium features could benefit from enhanced user guidance. Winner in this category |
| Security & Privacy Prod Apps's expert score for the 'Security & Privacy' aspect of each app. | 7.0 For security and privacy, we give Merlin AI a 7 out of 10. The app uses standard encryption for your conversations and personal data, which is good. However, since it connects to multiple AI providers, your data might be shared with these third-party services. This is mentioned in their privacy policy, but it's something to be aware of. The app doesn't ask for unnecessary permissions, but remember that your conversations and any documents you upload are processed by external AI services. While the company is transparent about how they use data, we would have liked more control over what gets shared with which AI providers. They do a good job of being upfront about it, but some users might want more control over their data. Winner in this category | 6.5 Habit Diary's security and privacy practices present a mixed picture that reflects the typical approach of freemium apps in the habit tracking space. While the app doesn't appear to have major security vulnerabilities, there are some privacy considerations that users should be aware of. We found no evidence of third-party analytics or tracking tools. The app only requests essential permissions, such as notifications for reminders. This commitment to privacy is rare and highly appreciated. However, there are some privacy concerns that impact our rating:
While Habit Diary doesn't appear to have any egregious privacy violations, the lack of clear information about data practices and the ad-supported model in the free version create uncertainty about how user information is handled. We rate security and privacy at 6.5 out of 10, acknowledging that while there are no major red flags, users should be aware of the potential data sharing implications of using the free version. |
| Conclusion A summary of our findings and final thoughts for each app. | Merlin AI stands out as an exceptional all-in-one AI assistant that successfully combines multiple AI models with practical tools. The generous free tier makes it accessible to everyone, while the premium features offer significant value for power users. For anyone looking to consolidate their AI tools into one powerful platform, Merlin AI delivers an impressive and well-rounded experience. | Habit Diary is a solid habit tracking app that offers a comprehensive set of features for building and maintaining good habits. While the free version has limitations and includes ads, the premium features provide good value for serious users. The app's strength lies in its user-friendly interface and the 30-day challenge system that helps users form lasting habits. However, the freemium model and ad-supported free version may not appeal to everyone. For users who want unlimited habits without paying, Habitive offers a completely free alternative. Those seeking a more elegant design might prefer HabitKit with its beautiful GitHub-style visualization. However, if you value the structured 30-day challenge approach and don't mind the freemium limitations, Habit Diary remains a solid choice in the competitive habit tracking space. |
| Our Recommendation | ||
