# Engineering Formulas vs Problems

The clearest difference is in-app purchases: Problems at none against Engineering Formulas's 3. Problems also leads on update cadence (every 2 weeks vs every 2 months). Engineering Formulas's advantage is iOS requirement (15.1 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. Engineering Formulas sells 3 in-app purchases, starting at $4.99 per 7 days. Problems asks for nothing beyond the download.

Engineering Formulas ships an update every 2 months, Problems every 2 weeks. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Engineering Formulas | Problems |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Size | 45 MB | 10 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Mobin Akhter](https://appshunter.io/developer/1812505286) | [Exact Science](https://appshunter.io/developer/6773016718) |

## What reviewers say

### Engineering Formulas

[App page](https://appshunter.io/ios/app/engineering-formulas-engiref/id6758258119)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Premium | $4.99 | per 7 days |
| Yearly Premium | $29.99 | per year |
| Lifetime Access | $54.99 | one-time |


### Problems

[App page](https://appshunter.io/ios/app/problems-math-and-logic/id6773016716)

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

**In-app purchases:** none


## Frequently asked questions

### Is Engineering Formulas free?

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

### Is Problems free?

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

### Do Engineering Formulas or Problems have ads?

Neither Engineering Formulas nor Problems shows ads.

### Which is updated more often, Engineering Formulas or Problems?

Engineering Formulas ships an update every 2 months, and Problems every 2 weeks. Most recently, Engineering Formulas was updated on October 25, 2026 and Problems on October 24, 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.*