# UDWriter vs BottleChallenge

The clearest difference is in-app purchases: BottleChallenge at none against UDWriter's 2. BottleChallenge also leads on update cadence (monthly vs every 2 months). UDWriter's advantage is iOS requirement (12.0 vs 15.1). On price, ads and device support there is nothing between them.

Both are free to download. UDWriter sells 2 one-off in-app purchases. BottleChallenge asks for nothing beyond the download.

UDWriter ships an update every 2 months, BottleChallenge monthly. The most recent releases landed on October 29, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | UDWriter | BottleChallenge |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 37.5% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Monthly** |
| Monetization | Free with in-app purchases | — |
| Size | 10 MB | 49 MB |
| Requires iOS | **12.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Shamrock Records, Inc.](https://appshunter.io/developer/443431466) | [FUNDACJA BRAINGREEN](https://appshunter.io/developer/1885235341) |

## What reviewers say

### UDWriter

[App page](https://appshunter.io/ios/app/udwriter/id632058683)

A handwriting memo app designed with Universal Design principles for intuitive use. Offers three color options and a simple swipe gesture to clear the screen. Accessible for all users from the first use.

**Highlights:** Universal Design principles, Handwriting memo functionality, Select 3 colors, Swipe to clear all, Intuitive for all users

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Development Support + Logo on/off option | $2.99 | one-time |
| Input Text by Using Speech Recognition | $4.99 | one-time |


### BottleChallenge

[App page](https://appshunter.io/ios/app/bottlechallenge-water-refill/id6760599802)

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

**In-app purchases:** none


## Frequently asked questions

### Is UDWriter free?

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

### Is BottleChallenge free?

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

### Do UDWriter or BottleChallenge have ads?

Neither UDWriter nor BottleChallenge shows ads.

### Which is updated more often, UDWriter or BottleChallenge?

UDWriter ships an update every 2 months, and BottleChallenge monthly. Most recently, UDWriter was updated on October 29, 2026 and BottleChallenge on October 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.*