# SignPrep vs Sigma Notepad Calculator

The clearest difference is in-app purchases: SignPrep at none against Sigma Notepad Calculator's 3. SignPrep also leads on update cadence (every 3 days vs every 4 weeks) and device support (3 vs 1). Sigma Notepad Calculator's advantage is iOS requirement (17.0 vs 26.0). On price and ads there is nothing between them.

Both are free to download. Sigma Notepad Calculator sells 3 in-app purchases, starting at $1.99 per month. SignPrep asks for nothing beyond the download.

SignPrep ships an update every 3 days, Sigma Notepad Calculator every 4 weeks. The most recent releases landed on October 19, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | SignPrep | Sigma Notepad Calculator |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 4 weeks |
| Size | 42 MB | 15 MB |
| Requires iOS | 26.0 | **17.0** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Daniel Yong (Singapore)](https://appshunter.io/developer/1887392234) | [Soules Studio Ltd](https://appshunter.io/developer/1883253392) |

## What reviewers say

### SignPrep

[App page](https://appshunter.io/ios/app/signprep/id6761029767)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### Sigma Notepad Calculator

[App page](https://appshunter.io/ios/app/sigma-notepad-calculator/id6768903761)

**Features:** Family Sharing

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $1.99 | per month |
| Annual | $14.99 | per year |
| Lifetime | $29.99 | one-time |


## Frequently asked questions

### Is SignPrep free?

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

### Is Sigma Notepad Calculator free?

Sigma Notepad Calculator is free to download, with in-app purchases available.

### Do SignPrep or Sigma Notepad Calculator have ads?

Neither SignPrep nor Sigma Notepad Calculator shows ads.

### Which is updated more often, SignPrep or Sigma Notepad Calculator?

SignPrep ships an update every 3 days, and Sigma Notepad Calculator every 4 weeks. Most recently, SignPrep was updated on October 19, 2026 and Sigma Notepad Calculator on October 8, 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.*