ViewPic 1.6 (more quality on big images, double tap t
the author of this app says:
A simple picture viewer.
Open file via file explorer (ES File Explorer, AndExplorer) or Gallery share, or enter directory name.
Show private images from current directory.
Double tap change zoom, fling right for next.
Ads supported(low impression)
o Best image quality
o Hide dir in gallery
o keep screen on ;)