Was testing #zappl from Chrome and android app. It works from Chrome but not on app (please refer to my screenshot, no option to add media). It doesn't work from Safari 9 too (I cannot update iOS using cellular data). I'm giving up zappl app for the second time :(
I am glad #busy is working for me both from Chrome on Android 6 and iPhone Safari 9 now.
Try zapple if you haven't.
Just go to your steemit wallet, click "permissions" and copy your "POSTING KEY". Go to zapple.com and login using your steemit username and your posting key (not the generated password).