Not a bad tumblr. app.

A big improvement over the "official" app. No problems with crashing, etc. Its only useful for casual scrolling, since it wont display photosets (only reads the 1st image and stops there), nor identify gifs (nor let you view/play them while scrolling. Still, an easy to use app, but stick to the free version.

mistereaon about imgTumble for Tumblr, v1.3