# Gravity OB1 vs Tower Stack

The clearest difference is in-app purchases: Tower Stack at none against Gravity OB1's 1. Gravity OB1's advantage is ads (none vs shown). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Gravity OB1 sells 1 one-off in-app purchase. Tower Stack asks for nothing beyond the download.

## The numbers

| Metric | Gravity OB1 | Tower Stack |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 5 days | — |
| Size | 25 MB | 93 MB |
| Requires iOS | 13.4 | **13.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Q8blog](https://appshunter.io/developer/380669318) | [润豪 庄](https://appshunter.io/developer/1786146827) |

## What reviewers say

### Gravity OB1

[App page](https://appshunter.io/ios/app/gravity-ob1/id6788852525)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Full Game | $3.99 | one-time |


### Tower Stack

[App page](https://appshunter.io/ios/app/tower-stack-world-tour/id6792726708)

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

**In-app purchases:** none


## Frequently asked questions

### Is Gravity OB1 free?

Gravity OB1 is free to download, with in-app purchases available.

### Is Tower Stack free?

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

### Do Gravity OB1 or Tower Stack have ads?

Tower Stack shows ads; Gravity OB1 does not.

---

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