# The Happiness Project vs Kinnu

The clearest difference is review sentiment: Kinnu at 87% against The Happiness Project's 33%. Kinnu also leads on rating (4.8 vs 3.9) and update cadence (every 6 days vs every 5 months). The Happiness Project's advantage is in-app purchases (none vs 4) and iOS requirement (13.0 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. Kinnu sells 4 in-app purchases, starting at $1.99 per month. The Happiness Project asks for nothing beyond the download.

Kinnu holds the better App Store score, 4.8 against 3.9. That said, the two scores are not equally well evidenced: Kinnu has 518 ratings behind it against 42, so its average is the more settled of the two. Written reviews point the same way: 33% of The Happiness Project's written reviews are positive against 87% of Kinnu's.

The Happiness Project ships an update every 5 months, Kinnu every 6 days. The most recent releases landed on November 2, 2026 and November 7, 2026 respectively.

## The numbers

| Metric | The Happiness Project | Kinnu |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.9 (42 ratings)](https://appshunter.io/ios/app/the-happiness-project/id1366965114/reviews) | **[4.8 (518 ratings)](https://appshunter.io/ios/app/kinnu-general-knowledge/id1625333066/reviews)** |
| Number of ratings | 42 | **518** |
| Positive reviews | 33.3% of reviews | **87.2% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 6 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 99 MB | 101 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 12+ |
| Developer | [UCL](https://appshunter.io/developer/611203777) | [Kinnu Limited](https://appshunter.io/developer/1625333068) |

## What reviewers say

### The Happiness Project

[App page](https://appshunter.io/ios/app/the-happiness-project/id1366965114)

Engage in short, enjoyable mini-games designed by scientists to contribute to real psychological and neuroscience research. Your gameplay and anonymous survey responses help study well-being, anxiety, and depression.

**Highlights:** Play mini-games for science, Contribute to psychology research, Study neuroscience of well-being, Anonymous surveys, Understand mental health, Citizen science project

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

**In-app purchases:** none


### Kinnu

[App page](https://appshunter.io/ios/app/kinnu-general-knowledge/id1625333066)

This app offers bite-sized learning content across a wide range of subjects, from psychology and science to history and technology. It utilizes cognitive science and a unique "Memory Shield" technology to help users retain information effectively, making learning engaging and fun.

**Highlights:** Bite-sized, expert-edited content, Memory Shield technology for retention, Gamified learning sessions, Community-driven content development, Knowledge Bank progress tracking, Interactive, adaptive questions, Audio versions of content

**Features:** Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $1.99 | per month |
| Kinnu Certificate | $7.99 | one-time |
| Kinnu Certificate | $14.99 | one-time |
| Kinnu Certificate | $19.99 | one-time |

**What reviewers like**

- 👍 Engaging learning experience
- 🚀 Efficient micro-learning format
- 🔒 No ads or subscriptions
- 💡 Wide range of interesting topics
- 👍 Gamified learning approach

**What reviewers complain about**

- 🐛 Occasional bugs and crashes
- 🐛 Syncing and progress issues
- 🐛 Inaccurate or incomplete information
- 🐛 AI-generated content quality concerns
- 🐛 Inability to contact developers

**Reported bugs**

- Frequent app crashes
- Progress and data loss issues
- Syncing problems
- Compatibility issues with older devices

**Requested features**

- Ability to highlight or take notes
- More in-depth content and sources
- Customization options (e.g., dark mode)
- Ability to connect with others
- Improved notification and reminder system


## Frequently asked questions

### Is The Happiness Project free?

The Happiness Project is free to download, with no in-app purchases.

### Is Kinnu free?

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

### Which has better reviews, The Happiness Project or Kinnu?

Kinnu is rated higher. The Happiness Project averages 3.9 out of 5 from 42 ratings, while Kinnu averages 4.8 from 518 ratings.

### Do The Happiness Project or Kinnu have ads?

Neither The Happiness Project nor Kinnu shows ads.

### Which is updated more often, The Happiness Project or Kinnu?

The Happiness Project ships an update every 5 months, and Kinnu every 6 days. Most recently, The Happiness Project was updated on November 2, 2026 and Kinnu on November 7, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*