Hehe....
Except my app has different buttons there, to Mark read or Delete...
My thinking is that if you're going to reply, you'll be typing anyway, getting a better hold on the device and then making multiple touches while typing, so two extra taps to first open a message and to hit "reply" probably don't matter much.
On the other hand, deleting an unneeded message or marking it read can be completed quickly...
Being able to add buttons is one of the features added in the platform in Android 4.1, and one user really got on my case about supporting it back then
