# Innerloop AI vs 66 Challenge

The clearest difference is update cadence: Innerloop AI at every 2 days against 66 Challenge's every 5 days. 66 Challenge's advantage is iOS requirement (13.0 vs 15.1). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Innerloop AI sells 2 in-app purchases, starting at $3.99 per month and 66 Challenge sells 3 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

Innerloop AI ships an update every 2 days, 66 Challenge every 5 days. The most recent releases landed on September 20, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | Innerloop AI | 66 Challenge |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (5 ratings)](https://appshunter.io/ios/app/66-challenge/id6758270405/reviews)** |
| Number of ratings | — | **5** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 2 days** | Every 5 days |
| Monetization | — | Freemium |
| Size | 42 MB | 18 MB |
| Requires iOS | 15.1 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 12+ |
| Developer | [Nikola Gavric](https://appshunter.io/developer/1863332873) | [Moad Ghajjate El Fal](https://appshunter.io/developer/1871890791) |

## What reviewers say

### Innerloop AI

[App page](https://appshunter.io/ios/app/innerloop-ai/id6756866856)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Innerloop Premium | $3.99 | per month |
| Innerloop Premium | $29.99 | per year |


### 66 Challenge

[App page](https://appshunter.io/ios/app/66-challenge/id6758270405)

Build lasting habits with a science-backed system designed to guide you through a 66-day journey. Track daily progress, visualize your transformation, and stay motivated with social features and achievements. Transform your life one habit at a time.

**Highlights:** Daily habit tracking, Progress visualization, Streak protection, Social feed and squads, Customizable reminders, Achievement badges

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $3.99 | per month |
| Pro Annual | $29.99 | per year |
| Pro Lifetime | $59.99 | one-time |


## Frequently asked questions

### Is Innerloop AI free?

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

### Is 66 Challenge free?

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

### Do Innerloop AI or 66 Challenge have ads?

Neither Innerloop AI nor 66 Challenge shows ads.

### Which is updated more often, Innerloop AI or 66 Challenge?

Innerloop AI ships an update every 2 days, and 66 Challenge every 5 days. Most recently, Innerloop AI was updated on September 20, 2026 and 66 Challenge on September 18, 2026.

---

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