# Trial&Error vs KnowTree

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.

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.

## The numbers

| Metric | Trial&Error | KnowTree |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | Yes |
| Update frequency | **Weekly** | Every 9 days |
| Size | 17 MB | 51 MB |
| Requires iOS | 15.4 | **15.1** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Naruhito Ozawa](https://appshunter.io/developer/1166703594) | [Ukon Ryohei](https://appshunter.io/developer/1834526187) |

## What reviewers say

### Trial&Error

[App page](https://appshunter.io/ios/app/trial-and-error/id1612021152)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly fee | $0.49 | per month |
| PremiumPlan(onetime-purchase) | $2.99 | one-time |


### KnowTree

[App page](https://appshunter.io/ios/app/knowtree/id6757321205)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| KnowTree Premium | $4.99 | one-time |


## Frequently asked questions

### Is Trial&Error free?

Trial&Error is free to download, with in-app purchases available.

### Is KnowTree free?

KnowTree is free to download, with in-app purchases available.

### Do Trial&Error or KnowTree have ads?

Both Trial&Error and KnowTree show ads.

### Which is updated more often, Trial&Error or KnowTree?

Trial&Error ships an update weekly, and KnowTree every 9 days. Most recently, Trial&Error was updated on September 13, 2026 and KnowTree on September 8, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*