# Gravity 21 vs MDS

Gravity 21 and MDS are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Gravity 21 ships an update every 5 weeks, MDS every 3 weeks. The most recent releases landed on November 3, 2026 and November 11, 2026 respectively.

## The numbers

| Metric | Gravity 21 | MDS |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Every 3 weeks** |
| Monetization | Free | — |
| Size | 29 MB | 20 MB |
| Requires iOS | 13.4 | 13.4 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Fitbase](https://appshunter.io/developer/1530906929) | [Alexey Likhatskiy](https://appshunter.io/developer/1535199061) |

## What reviewers say

### Gravity 21

[App page](https://appshunter.io/ios/app/gravity-21/id1668987927)

Manage your fitness club memberships and class schedules. Book group sessions, receive workout reminders, and track your membership validity. Stay updated with your fitness journey.

**Highlights:** View workout schedules, Book group training sessions, Receive workout reminders, Track membership expiry, Manage club services

**Features:** macOS Compatibility

**In-app purchases:** none


### MDS

[App page](https://appshunter.io/ios/app/mds/id6466178836)

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

**In-app purchases:** none


## Frequently asked questions

### Is Gravity 21 free?

Gravity 21 is free to download, with no in-app purchases.

### Is MDS free?

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

### Do Gravity 21 or MDS have ads?

Neither Gravity 21 nor MDS shows ads.

### Which is updated more often, Gravity 21 or MDS?

Gravity 21 ships an update every 5 weeks, and MDS every 3 weeks. Most recently, Gravity 21 was updated on November 3, 2026 and MDS on November 11, 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.*