# Lucid vs Mental Models

The clearest difference is in-app purchases: Lucid at none against Mental Models's 1. Mental Models's advantage is device support (3 vs 1) and iOS requirement (15.1 vs 18.6). On price and ads there is nothing between them.

Both are free to download. Mental Models sells 1 one-off in-app purchase. Lucid asks for nothing beyond the download.

## The numbers

| Metric | Lucid | Mental Models |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Size | 3 MB | 53 MB |
| Requires iOS | 18.6 | **15.1** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Saad Nasser](https://appshunter.io/developer/1785514743) | [Christos Tsavas](https://appshunter.io/developer/1887557969) |

## What reviewers say

### Lucid

[App page](https://appshunter.io/ios/app/lucid-think-clearly/id6758679042)

**Features:** macOS Compatibility

**In-app purchases:** none


### Mental Models

[App page](https://appshunter.io/ios/app/mental-models-mind-models/id6761058477)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Access | $6.99 | one-time |


## Frequently asked questions

### Is Lucid free?

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

### Is Mental Models free?

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

### Do Lucid or Mental Models have ads?

Neither Lucid nor Mental Models shows ads.

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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.*