Thanks for the suggestions. Descending sorts are now on the TODO list.
Selecting multiple files is accomplished by swiping horizontally across items and then using the File menu Cut/Copy/Delete items:
The context menu (tap and hold menu) currently only operates on the individual item on which it is pressed. I think this is better behavior...if we have the context menu operate on all items, it might be more confusing if some selected items are present only off the screen.
With regard to exiting the app...the home key is the "exit" key. From what I've seen, most popular Android file managers have the back key close the application and return you to the home screen when pressing it once or twice at the top level. When you press the back button at the top level, they raise a "toast message" indicating that you can "Press the back button again to exit". Most people seem to equate this with doing "File->Quit" in a desktop application, but that's not what's happening.
Each of these popular file managers does in fact close itself and take you to the home screen, but the app is very likely still loaded into memory. They're not doing anything wrong here...this is exactly how Android is supposed to work. The problem is that the Android application lifecycle is different than that of a desktop computer, i.e., Android *wants* to keep as many apps non-running cached/suspended in the background as possible.
The user manual for SystemPanel has some info on how Android works in this regard specifically see: Task Management | android.nextapp.com
I can certainly add a setting to make FX "exit" to the home screen like other file managers, but it won't actually terminate the app. Having an app actually terminate itself is bad design per Android engineers, see Dianne Hackborn's posts here: System.exit - Android Developers | Google Groups
I may wind up adding a "Favorites" or "Bookmarks" item either within the "Files" section or as its own "Favorites" section at the top level. I do want to have a bit more customization on the home screen as well, including the ability to eliminate items that you don't want.
Thanks again for the suggestions!