# Spark vs Japan Ready Function

The clearest difference is in-app purchases: Japan Ready Function at none against Spark's 2. Spark's advantage is update cadence (every 3 days vs every 6 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Spark sells 2 in-app purchases, starting at $0.99 per month. Japan Ready Function asks for nothing beyond the download.

Spark ships an update every 3 days, Japan Ready Function every 6 months. The most recent releases landed on October 6, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Spark | Japan Ready Function |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 6 months |
| Size | 63 MB | 51 MB |
| Requires iOS | **14.0.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [JNRA Legacy, LLC](https://appshunter.io/developer/1707021991) | [Career-Tech Japan Co.,LTD](https://appshunter.io/developer/1858175254) |

## What reviewers say

### Spark

[App page](https://appshunter.io/ios/app/spark-study-smarter/id6520395594)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Spark Premium Monthly | $0.99 | per month |
| Spark Premium Annual | $9.99 | per year |


### Japan Ready Function

[App page](https://appshunter.io/ios/app/japan-ready-function-lms/id6757743661)

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

**In-app purchases:** none


## Frequently asked questions

### Is Spark free?

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

### Is Japan Ready Function free?

Japan Ready Function is free to download, with no in-app purchases.

### Do Spark or Japan Ready Function have ads?

Neither Spark nor Japan Ready Function shows ads.

### Which is updated more often, Spark or Japan Ready Function?

Spark ships an update every 3 days, and Japan Ready Function every 6 months. Most recently, Spark was updated on October 6, 2026 and Japan Ready Function on October 2, 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.*