#51 - nice idea and nice concept. Maybe too much difference between app font and "solute" font, and I might like to try some other colors a bit less Mario Bros
#50 and 46 - a bit too easy, and I am not sure I want to focus so much on the "a" as an icon
#49 - nice, but somehow I feel that this kind of logo exists a lot out there
#47 - too childish