Background
In Android 4.4 (KitKat), Google suddenly cut off all third-party (non-preinstalled) applications from the permission to write to external/removable storage. Thanks to this decision, a lot of applications have been crippled and some have become entirely useless. Pressure on Google has led to a compromise solution that has been integrated into Android 5. Applications can regain the write permission to external storage using a new API together with SAF (Storage Access Framework). However, in general, external SD cards are always much less reliable (especially some combinations of devices/SD cards) than an internal memory.
First Start
- Directory picker will appear. You need to select the directory (or volume) with which you want to work.
- Tap the More button (top-right corner) and choose Show SD card.
- Tap the Menu button (top-left corner) and choose the storage you want to use.
- Tap SELECT (bottom).
Limitations
There are some limitations in the SAF mode you should know.
- SAF API provides much lower performance than the standard direct file access mode (especially with dirs that contain a lot of files/subdirs).
- Home/Custom directories cannot be set in SAF; however, the last-picked SAF URI is automatically saved: Home Button → Go to Last Picked SAF Dir.
- The wipe feature does not work. If option “Wipe after Encryption” is checked in the app settings, file(s) will be deleted only.
- The “Open File” function will work only if the destination application is able to decode the SAF URI.