# Prism vs 体重日记

The clearest difference is price: Prism at Free against 体重日记's $0.99. 体重日记's advantage is in-app purchases (none vs 1) and iOS requirement (17.6 vs 26.0). On update cadence, ads and device support there is nothing between them.

Prism is free to download; 体重日记 costs $0.99 up front. Prism sells 1 in-app purchase, starting at $1.99 per month. 体重日记 asks for nothing beyond the download.

Prism ships an update every 11 days, 体重日记 fortnightly. The most recent releases landed on October 28, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Prism | 体重日记 |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 11 days** | Fortnightly |
| Size | 3 MB | 12 MB |
| Requires iOS | 26.0 | **17.6** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [剑炜 陈](https://appshunter.io/developer/1868267178) | [创宏 陈](https://appshunter.io/developer/1884920634) |

## What reviewers say

### Prism

[App page](https://appshunter.io/ios/app/prism-sunlight-tracker/id6758259341)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Prism Premium (Monthly) | $1.99 | per month |


### 体重日记

[App page](https://appshunter.io/ios/app/id6762725091)

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

**In-app purchases:** none


## Frequently asked questions

### Is Prism free?

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

### Is 体重日记 free?

体重日记 costs $0.99, with no in-app purchases.

### Do Prism or 体重日记 have ads?

Neither Prism nor 体重日记 shows ads.

### Which is updated more often, Prism or 体重日记?

Prism ships an update every 11 days, and 体重日记 fortnightly. Most recently, Prism was updated on October 28, 2026 and 体重日记 on October 25, 2026.

---

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