Acrosync is the only iOS app that implements the rsync protocol, a fast, efficient, and reliable folder synchronization protocol supported by most Mac/Linux computers, NAS, or remote servers without server side installation.
As an rsync client, Acrosync lets you easily sync selected folders between your computers and your iOS devices. You just need one tap to start full folder sync, which is be smart enough to skip identical files and transfer only new or modified files. For modified files, it can even perform a differential sync algorithm and only transfer modified parts, in order to further save bandwidth and improve sync speed. File transfer can be encrypted to secure against unsafe networks, and verified using checksums to avoid corruptions. With advanced sync options, you can specify arbitrary port to connect, the connection protocol (ssh or rsync) to use, and so on. Selective sync is also supported by specifying include/exclude patterns, so you can sync only a certain set of files, and/or exclude files you don't want to sync.
All files are stored locally so you will always have offline access to all your documents, photos, videos, etc, on your devices all the time, even when there is no network connection. A slick and intuitive interface designed from mobile devices allows you to browse files easily and quickly. Almost all multimedia files and documents can be opened, including music, photo, movie, txt, html, pdf, word, excel, powerpoint, keynote, pages, numbers, and many others.
With new features introduced in the iOS 8 storage extension, Acrosync now acts as a private cloud drive that serve files for other apps -- filed stored in Acrosync can be easily shared by other apps using the universal document picker interface, without the need to switch to Acrosync. Changes made by other apps can be saved to Acrosync using the same interface, and synced back to computers automatically. As a result, Acrosync now behaves similarly to popular cloud drives such as iCloud, Dropbox, Box.net. However, with Acrosync you will always have the offline access and you can basically turn any computer into a private cloud server, without installing proprietary server software.
• Mac computers must have Remote Login enabled (System Preferences -> Sharing -> Remote Login).
• For Windows computers, openssh and rsync must be installed, both of which are freely available as independent packages, or as part of cygwin.
Acrosync is compatible with rsync hosting providers such as HiDrive and Strongspace, as well as major NASes like QNAP and Synology.
The rsync library used by Acrosync was built from scratch and recently released as an open-source project.
• Fixed a bug that may causes two errors: "unexpected flag" or "the ssh channel has been blocked for more than 120 seconds"
• Fixed video full screen playing
Ratings and Reviews
Syncs perfectly to device and has a built-in file manager that has its own file opening software for all file types. Only issue is you have to manually download or upload but that's no big deal for what I'm using it for since most changes are made on the server. Great app worth the money in my opinion!
Nice idea — flawed execution
The idea behind this app is great. Provide an easy way to sync files from your computer to the device without going through iTunes, and leverage rsync to do it efficiently. Unfortunately it suffers in reality.
* First, it requires initiating the connection from the device. I was under the impression that I could connect from the computer to the device but this was not the case.
* Second, you cannot sync individual files, only complete folders.
* Third, it fails rather badly at syncing a single large (550MB) file, repeatedly stalling out with no errors and requiring a relaunch of the app to close the stalled connection.
* And fourth, it behaves rather badly when attempting to display Bonjour services, to the extent that this functionality is unusable on any network with a sizable number of ssh services advertised.
If you're on a small network and you want to transfer a folder of small files, this app may be fine for you. But it simply won't do what I bought it for, which was to transfer a very small number of large files. Caveat emptor.
Edit: After discussion with the developer, I've raised my rating to 3 stars to reflect appreciation for a reasonably prompt response. I hope to be able to raise the rating again after the next update is released!
Great with Linux
This uses SSH and therefore works great for transfering files (pictures, videos, PDFs, websites) from a Linux PC to your iPad. Just install an SSH server on your PC and you can connect and sync any folder directly from your iPad.
Unfortunately one of the recent iOS updates broke fullscreen video with this app, hence only four stars.
With Family Sharing set up, up to six family members can use this app.