Trial&Error vs KnowTree
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.)
KnowTree
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◆ Organize notes in a "hierarchy" — and everything becomes clearer With most note-taking apps, as information piles up, it becomes hard to see how things are connected. "KnowTree" organizes your notes hierarchically with parent-child relationships. Group related information together so you can always find it again. --- ◆ Key Features [Tree Structure] Create nodes with parent-child relationships. Organize like "Main Topic → Subtopic → Details." No limit on how deep you can go. [Flexible Workflow] Start from the big picture (top-down), or jot down small notes and group them later (bottom-up) — both approaches work great. [Rich Content] Supports Markdown, images, links, and code blocks. Create notes that are clear and easy to read. --- ◆ Great For • Systematically organizing what you've learned • Structuring reading notes to match a book's outline • Managing project information in a hierarchy • Organizing your thoughts before writing • Connecting scattered notes into a coherent structure --- ◆ Features [Basic] • Create, edit, and delete nodes • Organize nodes with parent-child relationships • Markdown support • Search across all nodes • Trash (recover accidentally deleted notes) [Data Management] • Create and restore backups • Import data [Premium] • Create multiple trees • Ad-free experience • Premium color themes • Add images within note content • Export nodes • Home screen widget *Available with a Premium subscription (monthly) --- ◆ About Premium Plan Unlock all features with a monthly subscription. • Remove ads for a distraction-free experience • Access more color themes • Manage multiple trees for different purposes • Add images directly to your notes • Export in Markdown format • Quick access from your home screen You can cancel your subscription at any time. --- EULA (Apple Standard License Agreement) This app is subject to the Apple Media Services Standard End User License Agreement (Standard EULA). Apple Standard EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Terms of Use Use of this app is subject to the following terms: KnowTree Terms of Use: https://uconpa.com/chishikinoki/terms/ Privacy Policy For information on how we handle user data: KnowTree Privacy Policy: https://uconpa.com/chishikinoki/privacypolicy/
Screenshots
Verdict
Trial&Error and KnowTree are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
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 KnowTree sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
Trial&Error ships an update weekly, KnowTree every 9 days. The most recent releases landed on September 13, 2026 and September 8, 2026 respectively.
| Parameter | Trial&Error | KnowTree |
|---|---|---|
| Price | Free | Free |
| Update frequency | Weekly — better | Every 9 days |
| Ads | Yes | Yes |
| In-app purchases | Yes | Yes |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.4 | 15.1 — better |
| Further details — not scored | ||
| Size | 17 MB | 51 MB |
| Age rating | 4+ | 4+ |
| Developer | Naruhito Ozawa | Ukon Ryohei |
In-app purchases
Trial&Error
- Monthly fee$0.491 Month
- PremiumPlan(onetime-purchase)$2.99
KnowTree
- KnowTree Premium$4.99









