# iChemistry vs STILL PreOp

The clearest difference is update cadence: iChemistry at every 2 months against STILL PreOp's every 7 months. STILL PreOp's advantage is iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

iChemistry ships an update every 2 months, STILL PreOp every 7 months. The most recent releases landed on October 24, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | iChemistry | STILL PreOp |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 7 months |
| Size | 19 MB | 34 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Intersolia](https://appshunter.io/developer/946874318) | [CodeHero](https://appshunter.io/developer/1029552044) |

## What reviewers say

### iChemistry

[App page](https://appshunter.io/ios/app/ichemistry/id946874319)

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

**In-app purchases:** none


### STILL PreOp

[App page](https://appshunter.io/ios/app/still-preop/id1206366774)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is iChemistry free?

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

### Is STILL PreOp free?

STILL PreOp is free to download, with no in-app purchases.

### Do iChemistry or STILL PreOp have ads?

Neither iChemistry nor STILL PreOp shows ads.

### Which is updated more often, iChemistry or STILL PreOp?

iChemistry ships an update every 2 months, and STILL PreOp every 7 months. Most recently, iChemistry was updated on October 24, 2026 and STILL PreOp on October 26, 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.*