# MindDoom vs CalcGate | App Lock with Math

The clearest difference is iOS requirement: MindDoom at 18.5 against CalcGate | App Lock with Math's 26.2. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

MindDoom ships an update every 2 weeks, CalcGate | App Lock with Math every 3 weeks. The most recent releases landed on June 5, 2026 and September 12, 2026 respectively.

## The numbers

| Metric | MindDoom | CalcGate | App Lock with Math |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 3 weeks |
| Size | 117 MB | 4 MB |
| Requires iOS | **18.5** | 26.2 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 9+ | 4+ |
| Developer | [Justus Laske](https://appshunter.io/developer/1839776238) | [HIDEYUKI INAGAKI](https://appshunter.io/developer/1819355611) |

## What reviewers say

### MindDoom

[App page](https://appshunter.io/ios/app/minddoom/id6752542846)

**In-app purchases:** none


### CalcGate | App Lock with Math

[App page](https://appshunter.io/ios/app/calcgate-app-lock-with-math/id6762510886)

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

**In-app purchases:** none


## Frequently asked questions

### Is MindDoom free?

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

### Is CalcGate | App Lock with Math free?

CalcGate | App Lock with Math is free to download, with no in-app purchases.

### Do MindDoom or CalcGate | App Lock with Math have ads?

Neither MindDoom nor CalcGate | App Lock with Math shows ads.

### Which is updated more often, MindDoom or CalcGate | App Lock with Math?

MindDoom ships an update every 2 weeks, and CalcGate | App Lock with Math every 3 weeks. Most recently, MindDoom was updated on June 5, 2026 and CalcGate | App Lock with Math on September 12, 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.*