Shaun from PDA247 is raving in a review
about Resco Photo Viewer
, the popular image viewer for the Windows Mobile platform. In his own words,
NOTHING touches Resco Photo Viewer for image viewing and manipulation, NOTHING touches Resco Photo Viewer for programming efficiency and thoughful implementation and NOTHING touches Resco Photo Viewer for value for money. I simply cannot think of a way in which it could be improved.
I second that. If you are looking for a decent photo app to view your images while on the go, Resco is the right choice.