# Chrobox vs Underlairs

The clearest difference is update cadence: Chrobox at every 5 days against Underlairs's every 3 weeks. Underlairs's advantage is iOS requirement (15.0 vs 17.6). On price, review sentiment, ads and in-app purchases there is nothing between them.

Both are free to download. Chrobox sells 3 in-app purchases, starting at $3.99 per month and Underlairs sells 3 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

Chrobox ships an update every 5 days, Underlairs every 3 weeks. The most recent releases landed on September 10, 2026 and September 7, 2026 respectively.

## The numbers

| Metric | Chrobox | Underlairs |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (7 ratings)](https://appshunter.io/ios/app/underlairs-focus-study-timer/id6755931983/reviews)** |
| Number of ratings | — | **7** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 5 days** | Every 3 weeks |
| Monetization | Freemium | Freemium |
| Size | 95 MB | 230 MB |
| Requires iOS | 17.6 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [junhyeong kim](https://appshunter.io/developer/1773995986) | [John Jang](https://appshunter.io/developer/1857417631) |

## What reviewers say

### Chrobox

[App page](https://appshunter.io/ios/app/chrobox-ai-timebox-planner/id6755880209)

This app helps you block distracting applications and plan your day using AI-powered timeboxing. It guides you through brainstorming, prioritizing, scheduling tasks during your most focused hours, and reviewing your progress. Features include habit tracking, widgets, and AI analysis to understand your productivity patterns.

**Highlights:** AI-powered timeboxing, App blocking during focus time, Voice input for brainstorming, Drag-and-drop prioritization, Routine garden habit tracker, Lock Screen and Home Screen widgets, Weekly AI analysis and statistics

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| chrobox_monthly_subscription | $3.99 | per month |
| chrobox_yearly_subscription | $29.99 | per year |
| chrobox_lifetime | $39.99 | one-time |


### Underlairs

[App page](https://appshunter.io/ios/app/underlairs-focus-study-timer/id6755931983)

Enhance concentration and memory with curated ambient soundscapes and a focus timer. Choose from unique 'Lairs' and track your progress to achieve deep work and productivity goals.

**Highlights:** Focus Timer with customizable durations, Beast Mode for continuous music, Ambient soundscape playlists, Background playback, Lock screen controls, Stats tracking for focus minutes and streaks, Minimalist design

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Premium | $0.99 | per month |
| Yearly Premium | $9.99 | per year |
| Premium Lifetime Access | $17.99 | one-time |


## Frequently asked questions

### Is Chrobox free?

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

### Is Underlairs free?

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

### Do Chrobox or Underlairs have ads?

Neither Chrobox nor Underlairs shows ads.

### Which is updated more often, Chrobox or Underlairs?

Chrobox ships an update every 5 days, and Underlairs every 3 weeks. Most recently, Chrobox was updated on September 10, 2026 and Underlairs on September 7, 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.*