# One Thing vs Periodic Table & Element Guide

The clearest difference is ratings volume: One Thing at 892 against Periodic Table & Element Guide's 1. Periodic Table & Element Guide's advantage is rating (5.0 vs 4.7). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. One Thing sells 10 in-app purchases, starting at $7.99 per 7 days and Periodic Table & Element Guide sells 2 in-app purchases, starting at $3.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Periodic Table & Element Guide holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: One Thing has 892 ratings behind it against 1, so its average is the more settled of the two.

One Thing ships an update every 2 weeks, Periodic Table & Element Guide every 3 weeks. The most recent releases landed on November 8, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | One Thing | Periodic Table & Element Guide |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (892 ratings)](https://appshunter.io/ios/app/one-thing-earn-screen-time/id6748092391/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/periodic-table-and-element-guide/id6758946775/reviews)** |
| Number of ratings | **892** | 1 |
| Positive reviews | 27.1% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 3 weeks |
| Monetization | Free with in-app purchases | Freemium |
| Size | 227 MB | 8 MB |
| Requires iOS | 17.2 | **17** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [One Thing LTD](https://appshunter.io/developer/1824252786) | [Courtney Rawlings](https://appshunter.io/developer/1832354689) |

## What reviewers say

### One Thing

[App page](https://appshunter.io/ios/app/one-thing-earn-screen-time/id6748092391)

This app blocks distracting applications until a user completes a single, meaningful daily activity. It helps users break phone addiction, reduce mindless scrolling, and build real habits through a structured approach to digital detox and focused work sessions.

**Highlights:** Blocks distracting apps until daily activity is completed, AI-powered activity verification, System-level app blocking with native iOS integration, Focus timer with cross-device sync, Streak tracking and progress analytics, Personalized app filters and usage caps

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| One Thing (Full Access) (Weekly) | $7.99 | per 7 days |
| Pro Plan Monthly | $8.99 | per month |
| One Thing (Weekly) | $12.99 | per 7 days |
| Pro Plan Yearly WB | $21.90 | per year |
| One Thing (Full Access) (Annual) | $29.99 | per year |
| One Thing (Yearly - BF) | $29.99 | per year |
| One Thing Annual | $39.99 | per year |
| Pro Plan Yearly | $49.99 | per year |
| One Thing (Yearly) | $49.99 | per year |
| One Thing (Yearly) | $59.99 | per year |

**What reviewers like**

- 🚀 Helps stop doom-scrolling
- 👍 Beneficial for users
- 👍 Breaks bad habits
- 👍 Helps with productivity

**What reviewers complain about**

- 💰 Requires payment
- 🚫 Limited functionality without payment

**Reported bugs**

- Incompatible with younger users due to payment requirements

**Requested features**

- Allow multiple activities per day
- Add chores/cleaning/meal prep blocks
- Option to add multiple blocks


### Periodic Table & Element Guide

[App page](https://appshunter.io/ios/app/periodic-table-and-element-guide/id6758946775)

An interactive and offline reference for all 118 chemical elements. Explore detailed information, search, and filter elements with a clean, accessible design. Ideal for students, teachers, and chemistry enthusiasts.

**Highlights:** Interactive periodic table, Detailed element information, Offline functionality, Search and filter elements, Dark mode support, Save favorite elements

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Periodic Pro Weekly | $3.99 | per 7 days |
| Periodic Pro Lifetime | $29.99 | one-time |


## Frequently asked questions

### Is One Thing free?

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

### Is Periodic Table & Element Guide free?

Periodic Table & Element Guide is free to download, with in-app purchases available.

### Which has better reviews, One Thing or Periodic Table & Element Guide?

Periodic Table & Element Guide is rated higher. One Thing averages 4.7 out of 5 from 892 ratings, while Periodic Table & Element Guide averages 5.0 from 1 ratings.

### Do One Thing or Periodic Table & Element Guide have ads?

Neither One Thing nor Periodic Table & Element Guide shows ads.

### Which is updated more often, One Thing or Periodic Table & Element Guide?

One Thing ships an update every 2 weeks, and Periodic Table & Element Guide every 3 weeks. Most recently, One Thing was updated on November 8, 2026 and Periodic Table & Element Guide on October 31, 2026.

---

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