Comparison

Strontium vs Backup Disk

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Strontium

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
Read full description

Strontium app is the best way to manage all your photos, music, videos and files to or between your iPhone, iPad and iPod. Features and Benefits: - Secured data storage - Direct playback of videos and songs - Backup and restore contacts and camera roll - Lightning transfer between iPhone, iPad and iPod - Free app for auto file management and security Compatible with Strontium hardware: - Strontium iOS Lightning Card Reader Supported File Formats: Document: Pages, Numbers, Keynote, doc, docx, xls, xlsx, ppt, pptx, rtf, txt, html, pdf Image: jpg, png, bmp, gif, tif, tiff, ico, xbm, cur Audio: mp3, aac, aif, aiff, wav, m4a, caf Video: mp4, mov, m4v (without DRM), mkv, avi, flv, rm, rmvb, wmv, vob, 3gp Other: zip (In-App Purchase required) To experience more of our memory products visit www.strontium.biz

About

Backup Disk

Features
Read full description

Backup Disk turns your iPhone or iPad into a private backup disk for your Mac. Choose the folders you want to protect on your Mac, open Backup Disk on your iPhone or iPad, and sync them over Wi‑Fi with a single tap. Your files go straight from your Mac to your device — no accounts, no cloud, no tracking. WHY BACKUP DISK • Wireless: your Mac appears automatically on the same Wi‑Fi network, or connect with a cable. • Fast: only changed files are copied, and small files travel in large packages to make the most of your network. • Private: pair with the sync key shown on your Mac. Your files never pass through a server. • Always with you: browse your backups in the app or in the Files app, even offline. • Both ways: download any backed-up folder or file from your iPhone or iPad back to your Mac. • Picks up where it left off: if a sync is interrupted, the next one copies only what's left. HOW IT WORKS 1. Install Backup Disk on your Mac and on your iPhone or iPad. 2. On your Mac, add the folders you want to back up. 3. On your iPhone or iPad, choose your Mac, enter the sync key and tap Sync. BACKUP DISK PRO The free version stores up to 5 GB of backups per device and connects one device at a time. PRO removes the storage limit and lets you connect several iPhones and iPads to your Mac at once. One purchase unlocks PRO on iPhone, iPad and Mac with the same Apple Account. PRO is available as a monthly or yearly subscription, or as a one-time purchase. Payment is charged to your Apple Account at confirmation of purchase. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period. You can manage or cancel your subscription in your Apple Account settings. Terms of Use: https://backupdisk.mozkan.com/terms.html Privacy Policy: https://backupdisk.mozkan.com/privacy.html

Screenshots

Strontium4 screens
Backup Disk4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

UpkeepUpdate frequency

Strontium ships an update every 5 months, Backup Disk every 9 months. The most recent releases landed on November 6, 2026 and November 3, 2026 respectively.

Scorecard1 real difference · 9 level
Strontium versus Backup Disk: the parameters behind the verdict, then further details
ParameterStrontiumBackup Disk
PriceFreeFree
Rating1.8 (4 ratings) — better—
Positive reviews10.5% of reviews—
Number of ratings4 — better—
Update frequencyEvery 5 months — betterEvery 9 months
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPodiPhone, iPad, Mac
Requires iOS8.0 — better16.0
Further details — not scored
Size132 MB4 MB
Age rating4+4+
Developeri-FlashDrive Inc.Muharrem Ozkan

In-app purchases

2 purchases

Strontium

One-time2
  • Calendar BackupFree
  • Zip/unzip files support$0.99
3 purchases

Backup Disk

Subscriptions2
  • Backup Disk PRO Monthly$2.991 Month
  • Backup Disk PRO Annual3 Days trial$9.991 Year
One-time1
  • Backup Disk PRO Lifetime$19.99

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 3, 2026.

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