# Strontium vs Backup Disk

The clearest difference is iOS requirement: Strontium at 8.0 against Backup Disk's 16.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Strontium sells 2 one-off in-app purchases and Backup Disk sells 3 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

Strontium ships an update every 5 months, Backup Disk every 9 months. The most recent releases landed on November 6, 2026 and November 12, 2026 respectively.

## The numbers

| Metric | Strontium | Backup Disk |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.8 (4 ratings)](https://appshunter.io/ios/app/strontium/id1050123100/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 10.5% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 5 months** | Every 9 months |
| Monetization | Free with in-app purchases | — |
| Size | 132 MB | 4 MB |
| Requires iOS | **8.0** | 16.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [i-FlashDrive Inc.](https://appshunter.io/developer/1387757454) | [Muharrem Ozkan](https://appshunter.io/developer/443806426) |

## What reviewers say

### Strontium

[App page](https://appshunter.io/ios/app/strontium/id1050123100)

Easily manage and transfer photos, music, videos, and files between your Apple devices. Offers secure storage, direct media playback, and backup options for contacts and your camera roll.

**Highlights:** Secure data storage, Direct media playback, Backup and restore contacts, Lightning transfer between devices, Auto file management, Supports numerous file formats

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Calendar Backup | Free | one-time |
| Zip/unzip files support | $0.99 | one-time |


### Backup Disk

[App page](https://appshunter.io/ios/app/backup-disk/id6444174393)

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Backup Disk PRO Monthly | $2.99 | per month |
| Backup Disk PRO Annual | $9.99 | per year |
| Backup Disk PRO Lifetime | $19.99 | one-time |


## Frequently asked questions

### Is Strontium free?

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

### Is Backup Disk free?

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

### Do Strontium or Backup Disk have ads?

Neither Strontium nor Backup Disk shows ads.

### Which is updated more often, Strontium or Backup Disk?

Strontium ships an update every 5 months, and Backup Disk every 9 months. Most recently, Strontium was updated on November 6, 2026 and Backup Disk on November 12, 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.*