# Shelfmate vs Marcus

The clearest difference is in-app purchases: Shelfmate at none against Marcus's 2. Shelfmate also leads on update cadence (every 3 weeks vs every 2 months). Marcus's advantage is iOS requirement (16.4 vs 18.1). On price, ads and device support there is nothing between them.

Both are free to download. Marcus sells 2 in-app purchases, starting at $6.99 per month. Shelfmate asks for nothing beyond the download.

Shelfmate ships an update every 3 weeks, Marcus every 2 months. The most recent releases landed on October 21, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Shelfmate | Marcus |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 2 months |
| Monetization | Free | — |
| Size | 3 MB | 65 MB |
| Requires iOS | 18.1 | **16.4** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Mario Mouris](https://appshunter.io/developer/1376063231) | [Vukasin Rancic](https://appshunter.io/developer/1886442082) |

## What reviewers say

### Shelfmate

[App page](https://appshunter.io/ios/app/shelfmate-book-tracker/id6739967392)

Organize your personal library, track reading progress, and receive personalized book suggestions. This app prioritizes user privacy with secure iCloud storage and no analytics.

**Highlights:** Organize physical, eBook, and audiobook libraries, Track reading progress, AI-powered book recommendations, Goodreads import, Privacy-first data storage, iCloud synchronization

**In-app purchases:** none


### Marcus

[App page](https://appshunter.io/ios/app/marcus-book-and-reading-tracker/id6792703147)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Marcus Pro Monthly | $6.99 | per month |
| Marcus Pro Annual | $49.99 | per year |


## Frequently asked questions

### Is Shelfmate free?

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

### Is Marcus free?

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

### Do Shelfmate or Marcus have ads?

Neither Shelfmate nor Marcus shows ads.

### Which is updated more often, Shelfmate or Marcus?

Shelfmate ships an update every 3 weeks, and Marcus every 2 months. Most recently, Shelfmate was updated on October 21, 2026 and Marcus on October 9, 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.*