The black bars are annoying when viewing pics. I tried the free app and only have two suggestions; improve the swiping interface so it is more sensitive to small swipes, and implement syncing with Picasa and Facebook like the "JustPictures!" app.
Current Phone: Nexus 5 (Hammerhead) | Stock 4.4.4, Rooted, TWRP.
Previous Phones: Siemens S25 | Siemens S35 | Nokia 7110 | Nokia 7650 | HTC Himalaya | HTC Alpine | Samsung D500 | HTC Magician | Samsung I300 | HTC Artemis | HTC Kaiser | HTC Diamond | HTC Leo | Galaxy Nexus (Maguro)