It saves the day once again
Since version 1.7 there is ACRA (Application Crash Report for Android) libary incorporated into PhotoSorter. And already it has proved itself to be very useful. There were no crash reports on Android Market, but ACRA report was showing some NPEs while trying to get directory listing in some cases. I've conducted some research and have found out, that the program had been crashing if user had been trying to setup PhotoSorter while the storage device was unavailable. This was fixed in 1.8.