# Altadena Library District vs Understory

The clearest difference is in-app purchases: Altadena Library District at none against Understory's 6. Understory's advantage is update cadence (every 9 days vs every 16 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Understory sells 6 in-app purchases, starting at $4.99 per month. Altadena Library District asks for nothing beyond the download.

Altadena Library District ships an update every 16 months, Understory every 9 days. The most recent releases landed on September 30, 2026 and November 1, 2026 respectively.

## The numbers

| Metric | Altadena Library District | Understory |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.9 (60 ratings)](https://appshunter.io/ios/app/understory-reading-tracker/id6767701983/reviews)** |
| Number of ratings | — | **60** |
| Positive reviews | — | 95.8% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 16 months | **Every 9 days** |
| Monetization | — | Freemium |
| Size | 44 MB | 171 MB |
| Requires iOS | 16.0 | **15.1** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Altadena Library District](https://appshunter.io/developer/1813189236) | [Understory Studios LLC](https://appshunter.io/developer/1896501166) |

## What reviewers say

### Altadena Library District

[App page](https://appshunter.io/ios/app/altadena-library-district/id6745619928)

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

**In-app purchases:** none


### Understory

[App page](https://appshunter.io/ios/app/understory-reading-tracker/id6767701983)

This app helps you track your reading progress, set goals, and build a consistent reading habit. It features a unique plant aesthetic, social interaction with friends, and the ability to grow real-world trees by meeting reading objectives. Organize your library, share recommendations, and gain insights into your reading habits.

**Highlights:** Track reading progress and log books, Set reading goals and streaks, Grow real-world trees by meeting objectives, Social features for book groups and friends, Organize library with custom lists, Share book recommendations, View reading statistics and insights

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Understory Premium | $4.99 | per month |
| Understory Premium - Monthly | $4.99 | per month |
| Understory Premium | $49.99 | per year |
| Understory Premium - Yearly | $49.99 | per year |
| Streak Freeze | $0.99 | one-time |
| Streak Restore | $0.99 | one-time |


## Frequently asked questions

### Is Altadena Library District free?

Altadena Library District is free to download, with no in-app purchases.

### Is Understory free?

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

### Do Altadena Library District or Understory have ads?

Neither Altadena Library District nor Understory shows ads.

### Which is updated more often, Altadena Library District or Understory?

Altadena Library District ships an update every 16 months, and Understory every 9 days. Most recently, Altadena Library District was updated on September 30, 2026 and Understory on November 1, 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.*