# Writebulb vs Coloring Book for Amazon KDP

The clearest difference is ads: Writebulb at none against Coloring Book for Amazon KDP's shown. Writebulb also leads on update cadence (monthly vs every 2 months) and iOS requirement (15.5 vs 18.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Writebulb sells 1 one-off in-app purchase and Coloring Book for Amazon KDP sells 3 in-app purchases, starting at $6.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Writebulb ships an update monthly, Coloring Book for Amazon KDP every 2 months. The most recent releases landed on October 10, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | Writebulb | Coloring Book for Amazon KDP |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.3 (64 ratings)](https://appshunter.io/ios/app/coloring-book-for-amazon-kdp/id6736860429/reviews)** |
| Number of ratings | — | **64** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | **Monthly** | Every 2 months |
| Monetization | — | Free with in-app purchases |
| Size | 11 MB | 8 MB |
| Requires iOS | **15.5** | 18.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Brian Pirie](https://appshunter.io/developer/1676763468) | [Tzong Sheng Seet](https://appshunter.io/developer/1717569851) |

## What reviewers say

### Writebulb

[App page](https://appshunter.io/ios/app/writebulb/id6446223818)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| A Thousand Prompts | $2.99 | one-time |


### Coloring Book for Amazon KDP

[App page](https://appshunter.io/ios/app/coloring-book-for-amazon-kdp/id6736860429)

Easily create custom coloring books for Amazon KDP using AI-generated artwork. Design unique pages with various styles, create professional covers, and export print-ready PDFs. Turn your creative ideas into a sellable product.

**Highlights:** AI-generated custom artwork, Multiple art style options, Batch page creation, Integrated cover designer, User-friendly layout tools, KDP-ready PDF export, Prompt suggestions for inspiration

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly | $6.99 | per 7 days |
| Monthly | $29.99 | per month |
| Yearly | $99.99 | per year |


## Frequently asked questions

### Is Writebulb free?

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

### Is Coloring Book for Amazon KDP free?

Coloring Book for Amazon KDP is free to download, with in-app purchases available.

### Do Writebulb or Coloring Book for Amazon KDP have ads?

Coloring Book for Amazon KDP shows ads; Writebulb does not.

### Which is updated more often, Writebulb or Coloring Book for Amazon KDP?

Writebulb ships an update monthly, and Coloring Book for Amazon KDP every 2 months. Most recently, Writebulb was updated on October 10, 2026 and Coloring Book for Amazon KDP on October 14, 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.*