# Leanfast Play vs Physics Constants Library

The clearest difference is in-app purchases: Leanfast Play at none against Physics Constants Library's 1. Leanfast Play also leads on ads (none vs shown) and iOS requirement (16.4 vs 18.4). On price, update cadence and device support there is nothing between them.

Both are free to download. Physics Constants Library sells 1 one-off in-app purchase. Leanfast Play asks for nothing beyond the download.

Leanfast Play ships an update every 11 months, Physics Constants Library every 7 months. The most recent releases landed on October 9, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Leanfast Play | Physics Constants Library |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 11 months | **Every 7 months** |
| Size | 49 MB | 10 MB |
| Requires iOS | **16.4** | 18.4 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [The Members](https://appshunter.io/developer/1653824858) | [ChatStick Company Limited](https://appshunter.io/developer/1165816085) |

## What reviewers say

### Leanfast Play

[App page](https://appshunter.io/ios/app/leanfast-play/id6468610951)

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

**In-app purchases:** none


### Physics Constants Library

[App page](https://appshunter.io/ios/app/physics-constants-library/id6751224343)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock All Features | $2.99 | one-time |


## Frequently asked questions

### Is Leanfast Play free?

Leanfast Play is free to download, with no in-app purchases.

### Is Physics Constants Library free?

Physics Constants Library is free to download, with in-app purchases available.

### Do Leanfast Play or Physics Constants Library have ads?

Physics Constants Library shows ads; Leanfast Play does not.

### Which is updated more often, Leanfast Play or Physics Constants Library?

Leanfast Play ships an update every 11 months, and Physics Constants Library every 7 months. Most recently, Leanfast Play was updated on October 9, 2026 and Physics Constants Library on September 20, 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.*