# Alfredo Backer vs Stoichiometry Pro

The clearest difference is price: Alfredo Backer at Free against Stoichiometry Pro's $3.99. On update cadence, ads, in-app purchases and device support there is nothing between them.

Alfredo Backer is free to download; Stoichiometry Pro costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Alfredo Backer ships an update every 8 months, Stoichiometry Pro every 4 months. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Alfredo Backer | Stoichiometry Pro |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 4 months** |
| Size | 55 MB | 2 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Externato Alfredo Backer Ltda](https://appshunter.io/developer/1535072495) | [Roman Volinsky](https://appshunter.io/developer/977951850) |

## What reviewers say

### Alfredo Backer

[App page](https://appshunter.io/ios/app/alfredo-backer/id1212354980)

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

**In-app purchases:** none


### Stoichiometry Pro

[App page](https://appshunter.io/ios/app/stoichiometry-pro/id1546919546)

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

**In-app purchases:** none


## Frequently asked questions

### Is Alfredo Backer free?

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

### Is Stoichiometry Pro free?

Stoichiometry Pro costs $3.99, with no in-app purchases.

### Do Alfredo Backer or Stoichiometry Pro have ads?

Neither Alfredo Backer nor Stoichiometry Pro shows ads.

### Which is updated more often, Alfredo Backer or Stoichiometry Pro?

Alfredo Backer ships an update every 8 months, and Stoichiometry Pro every 4 months. Most recently, Alfredo Backer was updated on November 2, 2026 and Stoichiometry Pro on November 3, 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.*