# NoteifyApp vs Sigma

The clearest difference is in-app purchases: Sigma at none against NoteifyApp's 1. Sigma also leads on update cadence (every 2 days vs every 6 days). NoteifyApp's advantage is iOS requirement (16.0 vs 18.0). On price, ads and device support there is nothing between them.

Both are free to download. NoteifyApp sells 1 one-off in-app purchase. Sigma asks for nothing beyond the download.

NoteifyApp ships an update every 6 days, Sigma every 2 days. The most recent releases landed on September 30, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | NoteifyApp | Sigma |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 6 days | **Every 2 days** |
| Size | 43 MB | 7 MB |
| Requires iOS | **16.0** | 18.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Pratik Shirsat](https://appshunter.io/developer/1768491718) | [MAJOR Productions LLC](https://appshunter.io/developer/1885618341) |

## What reviewers say

### NoteifyApp

[App page](https://appshunter.io/ios/app/noteifyapp/id6683305707)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Noteify | $309.00 | one-time |


### Sigma

[App page](https://appshunter.io/ios/app/sigma-calculator/id6760669373)

**In-app purchases:** none


## Frequently asked questions

### Is NoteifyApp free?

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

### Is Sigma free?

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

### Do NoteifyApp or Sigma have ads?

Neither NoteifyApp nor Sigma shows ads.

### Which is updated more often, NoteifyApp or Sigma?

NoteifyApp ships an update every 6 days, and Sigma every 2 days. Most recently, NoteifyApp was updated on September 30, 2026 and Sigma on October 6, 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.*