# Prism vs SunSync

The clearest difference is device support: Prism at 3 against SunSync's 1. SunSync's advantage is iOS requirement (17.6 vs 26.0). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Prism sells 1 in-app purchase, starting at $1.99 per month and SunSync sells 2 in-app purchases, starting at $1.99 per year. Whichever you choose, the download price is not the number that matters.

Prism ships an update every 11 days, SunSync every 3 weeks. The most recent releases landed on October 11, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | Prism | SunSync |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 11 days** | Every 3 weeks |
| Size | 3 MB | 22 MB |
| Requires iOS | 26.0 | **17.6** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [剑炜 陈](https://appshunter.io/developer/1868267178) | [Marta Rodriguez](https://appshunter.io/developer/1873973295) |

## 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 |


### SunSync

[App page](https://appshunter.io/ios/app/sunsync-circadian-tracker/id6762293528)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Year | $1.99 | per year |
| Lifetime | $2.99 | one-time |


## Frequently asked questions

### Is Prism free?

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

### Is SunSync free?

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

### Do Prism or SunSync have ads?

Neither Prism nor SunSync shows ads.

### Which is updated more often, Prism or SunSync?

Prism ships an update every 11 days, and SunSync every 3 weeks. Most recently, Prism was updated on October 11, 2026 and SunSync on September 25, 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.*