# Missing Digits vs Shelf Clues

The clearest difference is in-app purchases: Shelf Clues at none against Missing Digits's 1. Shelf Clues also leads on update cadence (every 2 weeks vs monthly) and iOS requirement (15.6 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. Missing Digits sells 1 one-off in-app purchase. Shelf Clues asks for nothing beyond the download.

Missing Digits ships an update monthly, Shelf Clues every 2 weeks. The most recent releases landed on October 25, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Missing Digits | Shelf Clues |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Monthly | **Every 2 weeks** |
| Monetization | — | Free |
| Size | 1 MB | 44 MB |
| Requires iOS | 17.0 | **15.6** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [torankirite](https://appshunter.io/developer/1883564850) | [hackyeon kim](https://appshunter.io/developer/6782214891) |

## What reviewers say

### Missing Digits

[App page](https://appshunter.io/ios/app/missing-digits-math-puzzle/id6799607537)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $4.99 | one-time |


### Shelf Clues

[App page](https://appshunter.io/ios/app/shelf-clues/id6802747240)

A logic puzzle game where you deduce the correct placement of books on a shelf using clues about their colors, patterns, and positions. Swap books to solve increasingly complex arrangements and enjoy an endless stream of unique puzzles.

**Highlights:** Deduce book placement using clues, Swap books to rearrange shelves, Solve increasingly complex puzzles, Endless, procedurally generated levels, Simple controls, deep logic, Track clue satisfaction in real-time

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

**In-app purchases:** none


## Frequently asked questions

### Is Missing Digits free?

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

### Is Shelf Clues free?

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

### Do Missing Digits or Shelf Clues have ads?

Neither Missing Digits nor Shelf Clues shows ads.

### Which is updated more often, Missing Digits or Shelf Clues?

Missing Digits ships an update monthly, and Shelf Clues every 2 weeks. Most recently, Missing Digits was updated on October 25, 2026 and Shelf Clues on October 8, 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.*