# Prolog vs Study Timer Tracker

The clearest difference is price: Prolog at Free against Study Timer Tracker's $1.99. Prolog also leads on in-app purchases (none vs 2) and update cadence (every 2 days vs every 3 months). On ads, device support and iOS requirement there is nothing between them.

Prolog is free to download; Study Timer Tracker costs $1.99 up front. Study Timer Tracker sells 2 in-app purchases, starting at $0.99 per month. Prolog asks for nothing beyond the download.

Prolog ships an update every 2 days, Study Timer Tracker every 3 months. The most recent releases landed on September 20, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | Prolog | Study Timer Tracker |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 days** | Every 3 months |
| Size | 55 MB | 7 MB |
| Requires iOS | **17.6** | 18.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Elever (CA)](https://appshunter.io/developer/1769030097) | [Aneesh Pradeep](https://appshunter.io/developer/1836157821) |

## What reviewers say

### Prolog

[App page](https://appshunter.io/ios/app/prolog-screen-time-and-focus/id6695728427)

**Features:** macOS Compatibility

**In-app purchases:** none


### Study Timer Tracker

[App page](https://appshunter.io/ios/app/study-timer-tracker-studius/id6751641628)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Studius Pro Monthly | $0.99 | per month |
| Studius Pro - Annual | $6.99 | per year |


## Frequently asked questions

### Is Prolog free?

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

### Is Study Timer Tracker free?

Study Timer Tracker costs $1.99, and also offers in-app purchases.

### Do Prolog or Study Timer Tracker have ads?

Neither Prolog nor Study Timer Tracker shows ads.

### Which is updated more often, Prolog or Study Timer Tracker?

Prolog ships an update every 2 days, and Study Timer Tracker every 3 months. Most recently, Prolog was updated on September 20, 2026 and Study Timer Tracker on October 5, 2026.

---

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