# iStackz vs Sabai

The clearest difference is update cadence: Sabai at weekly against iStackz's every 4 weeks. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. iStackz sells 1 in-app purchase, starting at $1.99 per month and Sabai sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

iStackz ships an update every 4 weeks, Sabai weekly. The most recent releases landed on October 29, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | iStackz | Sabai |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/sabai-learn-thai/id6785896773/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 4 weeks | **Weekly** |
| Monetization | — | Freemium |
| Size | 3 MB | 48 MB |
| Requires iOS | 17.6 | **17.0** |
| Devices | **iPhone, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Christoph Luedi](https://appshunter.io/developer/918595512) | [Luis Halama](https://appshunter.io/developer/6785896955) |

## What reviewers say

### iStackz

[App page](https://appshunter.io/ios/app/istackz/id918620482)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full functionality - monthly | $1.99 | per month |


### Sabai

[App page](https://appshunter.io/ios/app/sabai-learn-thai/id6785896773)

Learn Thai effortlessly with daily words appearing on your phone's lock screen. This app integrates language learning into your daily routine without pressure, offering pronunciation, meaning, and practice tools.

**Highlights:** Lock screen widget for daily words, Thai script, pronunciation, and meaning, Customizable word frequency, Flashcard practice, Learning progress tracking, Favorite words and streaks

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Sabai Premium (Monthly) | $4.99 | per month |
| Sabai Premium (Yearly) | $17.99 | per year |


## Frequently asked questions

### Is iStackz free?

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

### Is Sabai free?

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

### Do iStackz or Sabai have ads?

Neither iStackz nor Sabai shows ads.

### Which is updated more often, iStackz or Sabai?

iStackz ships an update every 4 weeks, and Sabai weekly. Most recently, iStackz was updated on October 29, 2026 and Sabai on October 31, 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.*