# Möbius Sync — File sync with Syncthing

> iOS client for Syncthing, enabling peer-to-peer file synchronization. (iPhone/iPad app by Pickup Infinity Limited.)

- Source: https://appshunter.io/ios/app/mobius-sync/id1539203216 (this page in markdown: same URL + `.md`)
- Developer: [Pickup Infinity Limited](https://appshunter.io/developer/1118833408)
- Category: Productivity, Utilities
- Price: Free with in-app purchases
- Rating: 3.80/5 from 140 App Store ratings · 171 written reviews indexed
- Age rating: 4+
- Requires: iOS 14.1 · 23 MB
- Languages: American English, Arabic, Basque, Bulgarian, Catalan, Croatian, Czech, Danish, Dutch, Finnish and 27 more
- Released: 2020-11-22
- Data updated: 2026-08-24
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/mobius-sync/id1539203216/reviews.md

## What is Möbius Sync?

Möbius Sync brings Syncthing to your iPhone or iPad, allowing you to synchronize selected files between iOS devices and other devices supported by Syncthing, without the need for any cloud service.

Supports multiple folders and multiple remote devices. Synchronized folders can be created either:
1. in the Möbius Sync sandbox and files can be added to and retrieved from shared folders via the iOS Files app; or
2. (PAID feature) by accessing other apps' sandboxes. This feature is EXPERIMENTAL and may break other app's functionality.

Uses the open-source Syncthing engine internally.

Usage within the Möbius Sync sandbox is free up to 20MB. Unlimited file sync, including files in other apps' sanboxes is available for a one-time purchase.

NOTE: The functionality unlocked by in-app purchase is identical to that in Möbius Sync Pro (which is purchased up-front).

## Key features

- File synchronization between iOS and other Syncthing devices
- No cloud service required
- Supports multiple folders and remote devices
- Sync within app sandbox or other app sandboxes (paid)
- Uses open-source Syncthing engine

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Unlimited file sync | $4.99 | one-time |


## What do users think of Möbius Sync?

Overall sentiment: mixed

**Pros**

- ✅ Effective Syncthing implementation for iOS
- 💰 Fair one-time purchase model (no subscription)
- 🔒 Privacy-focused peer-to-peer syncing
- 📱 Good Files app integration
- ⚡ Fast file synchronization when working
- 🎯 Works well with Obsidian and Logseq
- 🛠️ Stable once properly configured
- 📂 Supports syncing large file collections

**Cons**

- 🐛 Outdated internal Syncthing version (1.28 vs 2.x)
- 💸 Aggressive paywall at 20MB free limit
- 🔌 No true background sync (iOS limitation)
- 🚫 Cannot sync iOS Photos app natively
- ⚠️ Inconsistent purchase restoration across devices
- 🔧 Complex setup and configuration required
- 📵 App stops syncing when closed or locked
- ❌ Limited selective sync capabilities
- 🐛 Frequent 'insufficient space' errors despite available storage
- 📞 Poor developer communication and support
- ⏱️ Infrequent app updates
- 🎨 Unintuitive UI (uses web interface)
- 🚫 No family sharing for in-app purchases
- 🐛 Purchase button non-functional on some devices

**Commonly reported bugs**

- Syncthing version incompatibility with v2.x devices
- Device discovery limited to 1 of 5 paired devices
- Insufficient space errors despite available storage
- Purchase dialog rendering issues on older devices
- Purchase not persisting after app reinstall
- Settings reset after app updates
- External folder bookmark path cannot be changed
- .stfolder sync failures and naming conflicts
- Sync hangs at intermediate percentages
- Files not appearing in designated folders despite sync confirmation
- App crashes and becomes unresponsive
- Language preference not saved between sessions
- Syncthing disabled errors with no explanation
- Quick Sync feature not working reliably
- Accessibility issues with VoiceOver
- App storage consuming excessive disk space (10GB+)

**Most requested features**

- Update internal Syncthing to version 2.x or higher
- iOS Photos app sync capability (at least one-way upload)
- True background synchronization
- Selective folder sync to save storage space
- File Provider extension for deeper iOS integration
- Widget for continuous background operation
- Photo library backup functionality
- Family sharing support for purchases
- Better UI/UX with custom frontend instead of web interface
- Automatic sync without manual app opening
- Support for untrusted devices
- Folder encryption support
- Location-based sync triggers
- More frequent Syncthing core updates
- Better documentation and setup guides

## Recent user reviews (10 of 171)

All indexed reviews: https://appshunter.io/ios/app/mobius-sync/id1539203216/reviews.md

### 1/5 — Abandoned

*2026-08-13*

This app is more trouble than its worth. Just please give me a widget that I can press to force a sync without needing to open the app every time.

### 1/5 — 20mb limit?!!

*2026-06-11*

Useless

### 3/5 — 2nd node couldn’t pick external folder

*2026-05-10*

I installed this for obsidian. I need to pick its folder as external folder from this app. But purchase and restore purchase dialog of this app didn’t function with unknown errors. Is only one device available?

### 1/5 — Not updated since 2024

*2026-05-07*

Mobius is currently on SyncThing v1.28.0 which was released on Oct 2024, leaving several security vulnerabilities open (search for CVEs for this version).

The current version of SyncThing is v2.0.16 as of May 2026 - please update!!!

### 5/5 — 🤩

*2026-05-06*

Ich bin Mega dankbar und happy über die App! Ihr seid die Besten!

Das ist so ein Krampf gewesen bisher, Dateien hin und her zu schieben zwischen Apple und Nicht-Apple-Sytemen, wenn man keine Cloud nutzen will.

Und jetzt synchronisiert sich das! Mit Syncthing! Und auch noch automatisch im Hintergrund! Der Hammer!! Ihr habt bestimmt n hohes Appletier dafür erpresst oder bestochen, damit das möglich wurde 🥸

### 3/5 — Open external folder doesn't work

*2026-04-14, version 1.28.0*

Title. Whenever I try to open a folder, and tap "external folder," it just doesn't work. No file explorer is brought up, no folder is created where I want it, etc.

### 1/5 — not updated

*2026-04-10, version 1.28.0*

latest version with breaking chang

### 1/5 — Old Syncthing Version

*2026-03-04*

I’ll revise my 1-Star rating when the internal Syncthing version 1.28 is updated to a 2.# release. Right now my iPhone can only see 1 of the 5 devices it’s paired with, and it can’t even sync files with it. The problem is all those devices are running Syncthing v2 and as they’re updated to newer and newer versions my iPhone has more and more trouble connecting with them. I could downgrade all my other devices to 1.28 but just no.

### 5/5 — best app in this category supports from algeria

*2026-02-19, version 1.28.0*

than you

### 5/5 — Bringt Syncthing auf iOS und iPadOS

*2026-02-12*

Die App funktioniert prima, um meine Daten mit verschiedenen Macs und PCs auf meinem iPhone und meinem iPad synchron zu halten. Zu Beginn war es für mich ungewohnt, dass Möbius gestartet werden muss, damit die Synchronisierung anläuft. Mittlerweile habe ich mich daran gewöhnt und finde es sogar sinnvoll, damit gezielt die Synchronisierung anstoßen zu können.
Es gibt von Syncthing neuere Versionen – hier wäre es schön, wenn der Entwickler die App ebenfalls auf dem aktuellen Stand halten könnte. Ich hoffe, der Entwickler pflegt die App weiter – sie ist echt ihr Geld wert.

## Frequently asked questions about Möbius Sync

### What does Möbius Sync do?

Möbius Sync allows you to synchronize selected files between your iPhone or iPad and other devices that support Syncthing. It operates without the need for any cloud service, facilitating direct peer-to-peer file transfers.

### What are the key features of Möbius Sync?

Key features include synchronizing files between iOS devices and other Syncthing-supported platforms, supporting multiple folders and remote devices, and the ability to sync within the app's sandbox or, with a paid upgrade, access other apps' sandboxes.

### How much does Möbius Sync cost?

Usage within the Möbius Sync sandbox is free for up to 20MB of file synchronization. Unlimited file sync, including syncing files in other apps' sandboxes, is available through a one-time purchase.

### What devices is Möbius Sync compatible with?

Möbius Sync is designed for iPhone and iPad devices. It synchronizes with other devices supported by the Syncthing protocol, which includes a wide range of desktop and mobile operating systems.

### What are common use cases for Möbius Sync?

Common use cases include keeping documents, photos, or project files consistent across your iPhone, iPad, and computer without relying on cloud storage. It's ideal for users who prioritize privacy and direct control over their data.

## Version history (last 5 releases)

### 1.28.0 — 2025-01-27

Incorporates Syncthing 1.28.0 (https://github.com/MobiusSync/MobiusSync/issues/210)

Enhancement: Support family sharing (https://github.com/MobiusSync/MobiusSync/issues/208)
Enhancement: Photo Collection option: export as read-only (https://github.com/MobiusSync/MobiusSync/issues/182)

Bug fix: External folder stops syncing after restore onto new device (https://github.com/MobiusSync/MobiusSync/issues/201)
Bug fix: Background crash reported via TestFlight (https://github.com/MobiusSync/MobiusSync/issues/211)
Bug fix: External Bookmarks Persist Even When Folders Are Removed (https://github.com/MobiusSync/MobiusSync/issues/188)
Bug fix: Vision Pro - camera used for QR Code scanning (https://github.com/MobiusSync/MobiusSync/issues/214)

### 1.27.10 — 2024-10-25

Incorporates Syncthing 1.27.10 (https://github.com/MobiusSync/MobiusSync/issues/191)

Adds Photo Collection folder options:
- toggle photos/videos/live photos (https://github.com/MobiusSync/MobiusSync/issues/178)
- set timezone for file stamping (https://github.com/MobiusSync/MobiusSync/issues/180)
- maximum assets to scan (https://github.com/MobiusSync/MobiusSync/issues/181)
- sync modified versions of photos/videos (https://github.com/MobiusSync/MobiusSync/issues/192)
- include in Folder Defaults (https://github.com/MobiusSync/MobiusSync/issues/198)

Other fixes/enhancements:
- fix flickering on reopening app after a while (https://github.com/MobiusSync/MobiusSync/issues/193)
- support syncing user-created folders under "On my iPhone" (https://github.com/MobiusSync/MobiusSync/issues/197)

### 1.27.9 — 2024-07-21

NEW: [Paid feature] Send your photos/videos from iOS to other Syncthing devices - the first EXPERIMENTAL implementation of send-only Photo Collection folders. Please consult the FAQ and GitHub, and provide your feedback to support the ongoing development of this feature.

Also:
- Upgraded to Syncthing 1.27.9 core
- Bug fix: Allowing pattern with vowel mutation in its name in .stignore doesn't work
- Bug fix: Settings dialogs do not reset fully to defaults between appearing

### 1.27.8 — 2024-06-23

Incorporates Syncthing 1.27.8.

Bug fixes and enhancements: https://github.com/MobiusSync/MobiusSync/milestone/8?closed=1

### 1.23.2 — 2023-03-07

Incorporates Syncthing 1.23.2.
Fixes problem with Filesystem Watcher Errors - now silently disabled as they serve no purpose on iOS.

## Apps similar to Möbius Sync

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Synctrain](https://appshunter.io/ios/app/synctrain/id6553985316) | 4.9 (123) | Free | Productivity |
| [Resilio Sync](https://appshunter.io/ios/app/resilio-sync/id1126282325) | 4.5 (844) | Free | Productivity |
| [Actions For Obsidian](https://appshunter.io/ios/app/actions-for-obsidian/id1659667937) | 4.8 (40) | Free | Productivity |
| [Cryptomator: Protect Privacy](https://appshunter.io/ios/app/cryptomator-protect-privacy/id1560822163) | 4.4 (410) | Free | Productivity |
| [KDE Connect](https://appshunter.io/ios/app/kde-connect/id1580245991) | 4.2 (271) | Free | Productivity |
| [KeePassium (KeePass passwords)](https://appshunter.io/ios/app/keepassium-keepass-passwords/id1435127111) | 4.7 (1,391) | Free | Productivity |

## More apps by Pickup Infinity Limited

- [TWiTfinity](https://appshunter.io/ios/app/twitfinity/id1498333767)
- [Heckle Live Streaming](https://appshunter.io/ios/app/heckle-live-streaming/id1562665499)
- [Möbius Sync Pro](https://appshunter.io/ios/app/mobius-sync-pro/id1671184333)

All apps by Pickup Infinity Limited: https://appshunter.io/developer/1118833408

## Related topics

[mobius](https://appshunter.io/ios/topics/mobius) · [syncthing](https://appshunter.io/ios/topics/syncthing) · [propel sync](https://appshunter.io/ios/topics/propel-sync) · [facebook sync](https://appshunter.io/ios/topics/facebook-sync) · [ksync](https://appshunter.io/ios/topics/ksync) · [sync for firefox](https://appshunter.io/ios/topics/sync-for-firefox) · [obsidian sync](https://appshunter.io/ios/topics/obsidian-sync) · [ixpand sync](https://appshunter.io/ios/topics/ixpand-sync)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-24.*