# Epicycles vs Sentian

The clearest difference is in-app purchases: Epicycles at none against Sentian's 2. Epicycles also leads on update cadence (every 5 days vs every 11 days). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Sentian sells 2 in-app purchases, starting at $7.99 per month. Epicycles asks for nothing beyond the download.

Epicycles ships an update every 5 days, Sentian every 11 days. The most recent releases landed on October 24, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | Epicycles | Sentian |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/epicycles/id6450433959/reviews)** | — |
| Number of ratings | **2** | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 5 days** | Every 11 days |
| Monetization | Free | — |
| Size | 4 MB | 63 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Limit Point Software](https://appshunter.io/developer/377981570) | [Xiaodi Su](https://appshunter.io/developer/1843948421) |

## What reviewers say

### Epicycles

[App page](https://appshunter.io/ios/app/epicycles/id6450433959)

Explore the visualization of complex Fourier series through interactive epicycles. Create and analyze approximations of parametric curves and complex functions. Save animations and export custom terms for later use.

**Highlights:** Visualize Fourier series of 2D functions, Create epicycles from drawn curves, Save custom terms to documents, Export animations as GIFs, Adjust time and number of terms, Interactive graphic elements

**Features:** macOS Compatibility

**In-app purchases:** none


### Sentian

[App page](https://appshunter.io/ios/app/sentian/id6753605054)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Premium | $7.99 | per month |
| Yearly Premium | $44.99 | per year |


## Frequently asked questions

### Is Epicycles free?

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

### Is Sentian free?

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

### Do Epicycles or Sentian have ads?

Neither Epicycles nor Sentian shows ads.

### Which is updated more often, Epicycles or Sentian?

Epicycles ships an update every 5 days, and Sentian every 11 days. Most recently, Epicycles was updated on October 24, 2026 and Sentian on October 15, 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.*