# Kernel 背單字 vs SubFit

The clearest difference is in-app purchases: Kernel 背單字 at none against SubFit's 2. SubFit's advantage is ads (none vs shown) and iOS requirement (15.0 vs 17.0). On price, update cadence and device support there is nothing between them.

Both are free to download. SubFit sells 2 in-app purchases, starting at $1.99 per month. Kernel 背單字 asks for nothing beyond the download.

Kernel 背單字 ships an update weekly, SubFit every 10 days. The most recent releases landed on September 19, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Kernel 背單字 | SubFit |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | **Weekly** | Every 10 days |
| Size | 63 MB | 12 MB |
| Requires iOS | 17.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Egan Bisma](https://appshunter.io/developer/1882424495) | [Cheng-Gang Wang](https://appshunter.io/developer/6790284003) |

## What reviewers say

### Kernel 背單字

[App page](https://appshunter.io/ios/app/kernel/id6760036064)

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

**In-app purchases:** none


### SubFit

[App page](https://appshunter.io/ios/app/subfit/id6790284001)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SubFit Plus 會員 | $1.99 | per month |
| SubFit Pro 會員 | $3.99 | per month |


## Frequently asked questions

### Is Kernel 背單字 free?

Kernel 背單字 is free to download, with no in-app purchases.

### Is SubFit free?

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

### Do Kernel 背單字 or SubFit have ads?

Kernel 背單字 shows ads; SubFit does not.

### Which is updated more often, Kernel 背單字 or SubFit?

Kernel 背單字 ships an update weekly, and SubFit every 10 days. Most recently, Kernel 背單字 was updated on September 19, 2026 and SubFit on September 9, 2026.

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