# Periodic Table PRO vs XLocker

The clearest difference is review sentiment: Periodic Table PRO at 50% against XLocker's 26%. Periodic Table PRO also leads on rating (4.6 vs 4.4) and iOS requirement (13.0 vs 16.0). XLocker's advantage is update cadence (every 9 days vs every 6 weeks) and ratings volume (1.3K vs 86). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Periodic Table PRO sells 8 one-off in-app purchases and XLocker sells 12 in-app purchases, starting at $3.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Periodic Table PRO holds the better App Store score, 4.6 against 4.4. That said, the two scores are not equally well evidenced: XLocker has 1.3K ratings behind it against 86, so its average is the more settled of the two. Written reviews point the same way: 50% of Periodic Table PRO's written reviews are positive against 26% of XLocker's.

Periodic Table PRO ships an update every 6 weeks, XLocker every 9 days. The most recent releases landed on September 18, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | Periodic Table PRO | XLocker |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (86 ratings)](https://appshunter.io/ios/app/periodic-table-pro/id1601545941/reviews)** | [4.4 (1.3K ratings)](https://appshunter.io/ios/app/xlocker-control-screen-time/id6447595893/reviews) |
| Number of ratings | 86 | **1.3K** |
| Positive reviews | **50.0% of reviews** | 25.9% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Every 9 days** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 210 MB | 34 MB |
| Requires iOS | **13.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [AGILE FLEX TECH SRL](https://appshunter.io/developer/1601049602) | [Nanjing Mairui Software Development Co., Ltd.](https://appshunter.io/developer/6783239280) |

## What reviewers say

### Periodic Table PRO

[App page](https://appshunter.io/ios/app/periodic-table-pro/id1601545941)

Explore a virtual chemistry lab with interactive experiments and detailed information on all chemical elements. Features include atom structure simulations, downloadable PDFs, and studying analytics to enhance learning. Supports multiple languages and offers a cohesive, functional design.

**Highlights:** Virtual chemistry lab with experiments, Detailed chemical element information, Atom structure simulations, Downloadable element PDFs, Studying analytics, Multi-language support

**Features:** macOS Compatibility

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SPECIAL OFFER! | $9.99 | one-time |
| Chernobyl experiments | $9.99 | one-time |
| Explosive experiments | $9.99 | one-time |
| Funny experiments | $9.99 | one-time |
| Experiments with fire | $9.99 | one-time |
| Gas bubbles experiments | $9.99 | one-time |
| Melting experiments | $9.99 | one-time |
| Oxidation experiments | $9.99 | one-time |


### XLocker

[App page](https://appshunter.io/ios/app/xlocker-control-screen-time/id6447595893)

Manage device usage with flexible screen time controls. Block specific apps, set schedules for study or leisure, and apply usage limits to prevent overuse. Location-based protections can also be enabled for designated apps.

**Highlights:** Block specific apps, Set app usage schedules, Apply app usage limits, Location-based app protection, Manage children's device time

**Features:** Family Sharing

**In-app purchases (12)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Upgrade to VIP | $3.99 | per 7 days |
| Upgrade to VIP | $5.99 | per month |
| Upgrade to VIP | $7.99 | per 7 days |
| Upgrade to VIP(3-day trial) | $7.99 | per 7 days |
| Upgrade to VIP | $9.99 | per year |
| Upgrade to VIP | $11.99 | per month |
| Upgrade to VIP(3-day trial) | $15.99 | per 7 days |
| Upgrade to VIP | $19.99 | per year |
| Upgrade to VIP | $19.99 | per year |
| Upgrade to VIP(3-day trial) | $39.99 | per year |
| Upgrade to lifetime VIP | $19.99 | one-time |
| Upgrade to lifetime VIP | $39.99 | one-time |

**What reviewers like**

- 👍 Nice
- 👍 This app is amazing
- 💯 Best screen time app
- 🙌 Thanks for dear developer

**What reviewers complain about**

- 🐛 Doesn't work on Facebook
- 🐛 Not Reliable
- 🐛 Not working
- 🐛 Glitchy and useless
- 🐛 Apps are missing on my phone

**Reported bugs**

- Occasional breaks where it gets stuck when typing password
- Unstable on iOS 16.5
- Search doesn't work well

**Requested features**

- Add Face ID
- 一键隐藏所有受保护的应用
- Advanced settings?


## Frequently asked questions

### Is Periodic Table PRO free?

Periodic Table PRO is free to download, with in-app purchases available.

### Is XLocker free?

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

### Which has better reviews, Periodic Table PRO or XLocker?

Periodic Table PRO is rated higher. Periodic Table PRO averages 4.6 out of 5 from 86 ratings, while XLocker averages 4.4 from 1.3K ratings.

### Do Periodic Table PRO or XLocker have ads?

Neither Periodic Table PRO nor XLocker shows ads.

### Which is updated more often, Periodic Table PRO or XLocker?

Periodic Table PRO ships an update every 6 weeks, and XLocker every 9 days. Most recently, Periodic Table PRO was updated on September 18, 2026 and XLocker on September 24, 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.*