# COLFRAY JP vs Prime Rush

The clearest difference is in-app purchases: COLFRAY JP at none against Prime Rush's 1. COLFRAY JP also leads on ads (none vs shown) and iOS requirement (15.1 vs 17). Prime Rush's advantage is update cadence (every 3 weeks vs every 2 months). On price and device support there is nothing between them.

Both are free to download. Prime Rush sells 1 one-off in-app purchase. COLFRAY JP asks for nothing beyond the download.

COLFRAY JP ships an update every 2 months, Prime Rush every 3 weeks. The most recent releases landed on September 24, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | COLFRAY JP | Prime Rush |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Size | 37 MB | 21 MB |
| Requires iOS | **15.1** | 17 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Uplift Educational Solutions](https://appshunter.io/developer/1793846825) | [Ayumu Izumi](https://appshunter.io/developer/1822273057) |

## What reviewers say

### COLFRAY JP

[App page](https://appshunter.io/ios/app/colfray-jp/id6471982954)

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

**In-app purchases:** none


### Prime Rush

[App page](https://appshunter.io/ios/app/prime-rush-math-time-attack/id6755986782)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Plan | $1.99 | one-time |


## Frequently asked questions

### Is COLFRAY JP free?

COLFRAY JP is free to download, with no in-app purchases.

### Is Prime Rush free?

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

### Do COLFRAY JP or Prime Rush have ads?

Prime Rush shows ads; COLFRAY JP does not.

### Which is updated more often, COLFRAY JP or Prime Rush?

COLFRAY JP ships an update every 2 months, and Prime Rush every 3 weeks. Most recently, COLFRAY JP was updated on September 24, 2026 and Prime Rush on September 10, 2026.

---

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