# Back in Time vs Molecules by Theodore Gray

Back in Time and Molecules by Theodore Gray both sit at 4.6 stars, but that hides the real split: 84% of Back in Time's written reviews are positive against 75% of Molecules by Theodore Gray's. Back in Time also leads on price ($7.99 vs $9.99). Molecules by Theodore Gray's advantage is device support (3 vs 1) and iOS requirement (12.1 vs 16.0). On rating, ratings volume, update cadence and ads there is nothing between them.

Back in Time costs $7.99 and Molecules by Theodore Gray $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 4.6 for Back in Time against 4.6 for Molecules by Theodore Gray. Both are backed by a comparable volume of ratings — 25 and 29 respectively. Written reviews are what separate them: 84% of Back in Time's written reviews are positive against 75% of Molecules by Theodore Gray's.

Back in Time ships an update every 7 months, Molecules by Theodore Gray every 6 months. The most recent releases landed on October 7, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Back in Time | Molecules by Theodore Gray |
| --- | --- | --- |
| Price | **$7.99** | $9.99 |
| Rating | [4.6 (25 ratings)](https://appshunter.io/ios/app/back-in-time/id450345693/reviews) | [4.6 (29 ratings)](https://appshunter.io/ios/app/molecules-by-theodore-gray/id923383841/reviews) |
| Number of ratings | 25 | **29** |
| Positive reviews | **83.7% of reviews** | 74.7% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 6 months** |
| Monetization | Paid | Paid |
| Size | 836 MB | 745 MB |
| Requires iOS | 16.0 | **12.1** |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 12+ |
| Developer | [Landka](https://appshunter.io/developer/450345696) | [NatureGuides Ltd.](https://appshunter.io/developer/310574314) |

## What reviewers say

### Back in Time

[App page](https://appshunter.io/ios/app/back-in-time/id450345693)

Explore the history of the Universe, Earth, Life, and Civilization through an immersive, interactive journey. This app uses custom animations, timelines, and interesting facts to bring historical events to life. It's designed to help users understand the connections between events and see the bigger picture.

**Highlights:** Interactive timeline of events, Custom animations and videos, Over 350 remarkable images, Little-known interesting facts, Offline access, Multilingual support

**Features:** macOS Compatibility

**In-app purchases:** none


### Molecules by Theodore Gray

[App page](https://appshunter.io/ios/app/molecules-by-theodore-gray/id923383841)

Explore the molecular world with interactive simulations and detailed information. Discover how elements form compounds and witness the dynamic dance of quantum mechanics through touch. This app offers a fun and educational way to understand the nature of substances.

**Highlights:** Touch-interactive molecular dynamics simulation, Bend, squeeze, and shape molecules, Adjust temperature to observe reactions, Full text of the 'Molecules' book, Interactive object rotations, Dozens of 'still life videos'

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Back in Time free?

Back in Time costs $7.99, with no in-app purchases.

### Is Molecules by Theodore Gray free?

Molecules by Theodore Gray costs $9.99, with no in-app purchases.

### Which has better reviews, Back in Time or Molecules by Theodore Gray?

Back in Time and Molecules by Theodore Gray are both rated 4.6 out of 5 on the App Store, from 25 and 29 ratings respectively.

### Do Back in Time or Molecules by Theodore Gray have ads?

Neither Back in Time nor Molecules by Theodore Gray shows ads.

### Which is updated more often, Back in Time or Molecules by Theodore Gray?

Back in Time ships an update every 7 months, and Molecules by Theodore Gray every 6 months. Most recently, Back in Time was updated on October 7, 2026 and Molecules by Theodore Gray on October 13, 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.*