# Booster OS vs Countdown Days

The clearest difference is rating: Countdown Days at 5.0 against Booster OS's 3.0. Countdown Days also leads on update cadence (every 3 days vs every 3 weeks). Booster OS's advantage is iOS requirement (15.6 vs 26.0). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Countdown Days holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

Booster OS ships an update every 3 weeks, Countdown Days every 3 days. The most recent releases landed on August 20, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | Booster OS | Countdown Days |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (1 ratings)](https://appshunter.io/ios/app/booster-os/id6746039279/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/countdown-days-jonapus/id6779926012/reviews)** |
| Number of ratings | 1 | 1 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 3 days** |
| Monetization | Free | Free |
| Size | 137 MB | 5 MB |
| Requires iOS | **15.6** | 26.0 |
| Devices | iPhone, iPod | **iPhone, iPad, Apple Watch** |
| Age rating | 17+ | 4+ |
| Developer | [Booster Robotics Technology Co., Ltd](https://appshunter.io/developer/1814806865) | [卫中 张](https://appshunter.io/developer/6776171165) |

## What reviewers say

### Booster OS

[App page](https://appshunter.io/ios/app/booster-os/id6746039279)

Control your intelligent robot with this platform. Connect easily, view live feeds, and access a library of actions and agents. Customize robot behavior and receive automatic updates for new features.

**Highlights:** Bluetooth setup, Real-time camera feeds, Action library, Multiple agents, Customizable actions, Automatic system updates

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

**In-app purchases:** none


### Countdown Days

[App page](https://appshunter.io/ios/app/countdown-days-jonapus/id6779926012)

An elegant countdown utility with a fluid glass design to track important moments. Features interactive widgets, push notification reminders, and seamless device syncing. Built natively for speed and a stunning user experience.

**Highlights:** Glassmorphic UI elements, Interactive Lock Screen widgets, Home Screen widgets, Push notification reminders, Cross-device syncing, Native SwiftUI development

**Features:** macOS Compatibility, Apple Watch app, iMessage stickers, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Booster OS free?

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

### Is Countdown Days free?

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

### Which has better reviews, Booster OS or Countdown Days?

Countdown Days is rated higher. Booster OS averages 3.0 out of 5 from 1 ratings, while Countdown Days averages 5.0 from 1 ratings.

### Do Booster OS or Countdown Days have ads?

Neither Booster OS nor Countdown Days shows ads.

### Which is updated more often, Booster OS or Countdown Days?

Booster OS ships an update every 3 weeks, and Countdown Days every 3 days. Most recently, Booster OS was updated on August 20, 2026 and Countdown Days on September 10, 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.*