# PIDL vs Shelfie

The clearest difference is update cadence: PIDL at every 4 weeks against Shelfie's every 4 months. PIDL also leads on device support (3 vs 1) and iOS requirement (12.0 vs 17.6). On price, 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.

PIDL ships an update every 4 weeks, Shelfie every 4 months. The most recent releases landed on October 6, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | PIDL | Shelfie |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 weeks** | Every 4 months |
| Size | 60 MB | 13 MB |
| Requires iOS | **12.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 9+ |
| Developer | [Xentral Methods](https://appshunter.io/developer/464707106) | [Mehmet Tarhan](https://appshunter.io/developer/1317600459) |

## What reviewers say

### PIDL

[App page](https://appshunter.io/ios/app/pidl/id914262569)

**Features:** macOS Compatibility

**In-app purchases:** none


### Shelfie

[App page](https://appshunter.io/ios/app/shelfie-reading-tracker/id6757387402)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is PIDL free?

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

### Is Shelfie free?

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

### Do PIDL or Shelfie have ads?

Neither PIDL nor Shelfie shows ads.

### Which is updated more often, PIDL or Shelfie?

PIDL ships an update every 4 weeks, and Shelfie every 4 months. Most recently, PIDL was updated on October 6, 2026 and Shelfie on October 2, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*