# DrillLock vs Modify PDF Pro

The clearest difference is update cadence: DrillLock at every 5 days against Modify PDF Pro's every 6 months. Modify PDF Pro's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.0). On price, ads and in-app purchases there is nothing between them.

Both are free to download. DrillLock sells 2 in-app purchases, starting at $6.99 per month and Modify PDF Pro sells 3 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

DrillLock ships an update every 5 days, Modify PDF Pro every 6 months. The most recent releases landed on October 13, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | DrillLock | Modify PDF Pro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/drilllock-math-app-blocker/id6759181330/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 5 days** | Every 6 months |
| Monetization | Freemium | — |
| Size | 8 MB | 75 MB |
| Requires iOS | 17.0 | **15.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [FRONTLINE LLC](https://appshunter.io/developer/1877229947) | [Jose Antonio Salinas Garcia](https://appshunter.io/developer/1803226958) |

## What reviewers say

### DrillLock

[App page](https://appshunter.io/ios/app/drilllock-math-app-blocker/id6759181330)

This app requires users to solve a math problem before accessing distracting applications, helping to create focused study sessions. It offers scheduled blocking, usage limits, and temporary unlocks for essential apps. A pro subscription unlocks advanced features for serious learners.

**Highlights:** Math challenge to unlock apps, Scheduled app blocking, Usage limit blocking, Temporary unlocks, Essential app exceptions, Multiple rule support (Pro)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| DrillLock PRO Monthly | $6.99 | per month |
| DrillLock PRO Yearly | $39.99 | per year |


### Modify PDF Pro

[App page](https://appshunter.io/ios/app/modify-pdf-pro/id6760251517)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Smart OCR Mensual | $3.99 | per month |
| Smart OCR Anual | $34.99 | per year |
| Cuenta premium vitalicia | $69.99 | one-time |


## Frequently asked questions

### Is DrillLock free?

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

### Is Modify PDF Pro free?

Modify PDF Pro is free to download, with in-app purchases available.

### Do DrillLock or Modify PDF Pro have ads?

Neither DrillLock nor Modify PDF Pro shows ads.

### Which is updated more often, DrillLock or Modify PDF Pro?

DrillLock ships an update every 5 days, and Modify PDF Pro every 6 months. Most recently, DrillLock was updated on October 13, 2026 and Modify PDF Pro 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.*