# interChem vs OpenAthena

The clearest difference is update cadence: interChem at every 3 weeks against OpenAthena's every 2 months. 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.

interChem ships an update every 3 weeks, OpenAthena every 2 months. Both last shipped on November 3, 2026.

## The numbers

| Metric | interChem | OpenAthena |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/interchem/id1549651849/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 2 months |
| Monetization | Free | — |
| Size | 1 MB | 74 MB |
| Requires iOS | 14.0 | 14.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [interfinity Limited](https://appshunter.io/developer/1774724445) | [Robert Krupczak](https://appshunter.io/developer/1686231817) |

## What reviewers say

### interChem

[App page](https://appshunter.io/ios/app/interchem/id1549651849)

Calculate atomic and molecular masses, element percentages, and view a periodic table. Features dynamic font sizing and Split View support for iPad.

**Highlights:** Atomic and molecular mass calculation, Element percentage calculation, Periodic table with element classification, Dynamic font size support, Split View and drag-and-drop for iPad

**In-app purchases:** none


### OpenAthena

[App page](https://appshunter.io/ios/app/openathena/id6448763554)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is interChem free?

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

### Is OpenAthena free?

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

### Do interChem or OpenAthena have ads?

Neither interChem nor OpenAthena shows ads.

### Which is updated more often, interChem or OpenAthena?

interChem ships an update every 3 weeks, and OpenAthena every 2 months. Most recently, interChem was updated on November 3, 2026 and OpenAthena on November 3, 2026.

---

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