# CIS vs Gravity

The clearest difference is update cadence: Gravity at every 9 days against CIS's every 3 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. CIS sells 1 in-app purchase, starting at $9.00 per month and Gravity sells 6 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

CIS ships an update every 3 months, Gravity every 9 days. The most recent releases landed on October 6, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | CIS | Gravity |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.1 (39 ratings)](https://appshunter.io/ios/app/gravity-language-immersion/id6769900394/reviews)** |
| Number of ratings | — | **39** |
| Positive reviews | — | 67.9% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 9 days** |
| Monetization | — | Free with in-app purchases |
| Size | 4 MB | 109 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ambitionz Apps](https://appshunter.io/developer/1764753535) | [Heimdall Space Inc.](https://appshunter.io/developer/1896698357) |

## What reviewers say

### CIS

[App page](https://appshunter.io/ios/app/cis-vr-practice-test/id6767673279)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| CIS-VR Practice Test | $9.00 | per month |


### Gravity

[App page](https://appshunter.io/ios/app/gravity-language-immersion/id6769900394)

Learn Japanese by capturing real-world text from your surroundings. This app creates personalized flashcards and study plans based on the vocabulary you encounter daily, making learning practical and context-driven.

**Highlights:** Personalized learning plans, Instant vocabulary extraction from photos, Smart review system, Context-based flashcards, Immersion-focused learning, Daily learning sessions

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| special offer | $4.99 | per month |
| Fluency | $6.99 | per 7 days |
| Immersive Monthly | $8.99 | per month |
| Immersive Monthly | $11.99 | per month |
| Immersion | $14.99 | per month |
| Polyglot | $69.99 | per year |


## Frequently asked questions

### Is CIS free?

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

### Is Gravity free?

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

### Do CIS or Gravity have ads?

Neither CIS nor Gravity shows ads.

### Which is updated more often, CIS or Gravity?

CIS ships an update every 3 months, and Gravity every 9 days. Most recently, CIS was updated on October 6, 2026 and Gravity 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.*