Trial&Error vs Focus4
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Trial&Error
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Trail and error is an app that looks back on what you have done and how you can modify your actions to better achieve your goals. You can use this app like how you would use a sticky note on a board. Organize your thoughts and categorize them into what you have already tried , what you were able to accomplish, what you can try next. Similar to the KPT (keep, problem, try) method, this is a retrospective method. The content entered is saved on your device. not sent to a server. Making your data secure. Alternatively you can upload your note to iCloud for backup. In the future, if the number of users increases, we may add a function to share / post the described data, but when adding the function, sharing / posting will be executed by the user's operation. Details will be described in the version upgrade information. The functions of this application are as follows. [Function] ・List multiple things you want to achieve ・ A list of trial and error actions is displayed, such as "What to try", "What you could do", "What you understood", "What to do next". ・ Backup to iCloud and data loading from iCloud. [Terms of use] https://oz-app.blogspot.com/p/blog-page_5.html (You can switch languages from Translate at the top of the page.) [Privacy policy] https://oz-app.blogspot.com/p/blog-page_38.html (You can switch languages from Translate at the top of the page.)
Focus4
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“Focus for 4 Hours a Day, Achieve Your Biggest Goals.” What if you could get more done in 4 focused hours than an entire day of scattered effort? Inspired by productivity systems like "The 4-Hour Workweek", Focus4 helps you build unstoppable focus, complete tasks, and develop strong daily habits to achieve your dreams. Why 4 Hours? Research shows that the human brain can only maintain deep focus for a limited period. By dedicating just 4 hours of deep, undistracted focus each day, you’ll maximize productivity, accomplish meaningful work, and build streaks that matter. As Tim Ferriss said in "The 4-Hour Workweek": "Focus on being productive instead of busy." Focus4 brings this philosophy to life—helping you create focus habits while keeping the process fun, rewarding, and effective. Key Features: Focus 4 Hours Daily on Your Goals - Commit to 4 hours of focused time every day. - Break free from distractions and achieve more with deep work sessions. AI-Powered Break Suggestions - Meet "Ticki", your AI bird companion! - After completing your focus hours, Ticki provides personalized activity suggestions tailored to your interests. - Stay refreshed and balanced while keeping productivity high. Build Habit Streaks & Track Progress - Stay motivated by completing daily 4-hour sessions. - View your progress on the calendar tracker. - Tap any completed day to see the fun activities suggested for your breaks. Earn Rewards & Have Fun - Earn "Seeds" (points) for completing focus sessions. - Use Seeds to feed Ticki or unlock more fun, AI-powered break suggestions. - Make productivity a game and enjoy building positive habits. Customize Your Experience - Ticki tailors its suggestions to align with your interests, keeping you motivated and inspired every day. How Focus4 Works: 1. Choose Your Interest: On first launch, select what you like to do on your free time. 2. Focus for 4 Hours: Complete a 4-hour session, broken into manageable chunks to suit your needs. 3. Get AI Break Suggestions: After finishing your session, Ticki rewards you with an activity suggestion to relax, recharge, or grow personally. 4. Track Your Streak: Build a habit streak by completing 4-hour sessions daily. Watch your progress grow! 5. Earn & Spend Seeds: Use your earned Seeds to feed Ticki and unlock more suggestions. Why Choose Focus4? Focus4 isn’t just another timer app—it’s a full productivity system designed to: - Help you build lasting habits of focus and discipline. - Keep you motivated with rewards, progress tracking, and AI-powered fun. - Encourage balanced productivity with suggestions that relax and inspire you after focused work. Whether you're studying, working on personal goals, or simply trying to make the most of your time, Focus4 is your companion to unlock deep focus and achieve results. Start Today, Build Tomorrow Focus4 turns productivity into a habit—and makes it fun along the way. Commit to 4 hours, break distractions, and see how much you can achieve with focused time and daily streaks. Terms & Conditions: https://www.focus4.kirlosyousef.com/terms_and_conditions.html Privacy Policy: https://www.focus4.kirlosyousef.com/privacy_policy.html
Screenshots
Verdict
The clearest difference is ads: Focus4 at none against Trial&Error's shown. Trial&Error's advantage is update cadence (weekly vs every 6 weeks) and iOS requirement (15.4 vs 17.6). On price, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Trial&Error sells 2 in-app purchases, starting at $0.49 per month and Focus4 sells 2 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.
Trial&Error ships an update weekly, Focus4 every 6 weeks. The most recent releases landed on September 13, 2026 and June 8, 2026 respectively.
| Parameter | Trial&Error | Focus4 |
|---|---|---|
| Price | Free | Free |
| Update frequency | Weekly — better | Every 6 weeks |
| Ads | Yes | No — better |
| In-app purchases | Yes | Yes |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.4 — better | 17.6 |
| Further details — not scored | ||
| Size | 17 MB | 9 MB |
| Age rating | 4+ | 4+ |
| Developer | Naruhito Ozawa | Kirlos Yousef |
In-app purchases
Trial&Error
- Monthly fee$0.491 Month
- PremiumPlan(onetime-purchase)$2.99
Focus4
- Premium Membership (Monthly)$2.991 Month
- Premium Membership3 Days trial$19.991 Year









