Glad you like it

The auto-scrolling does need some work and finer control and a way to start/stop the scrolling easily are on my todo-list. I haven't made any tests regarding power efficiency but I going take a look at it at some point.

For now I'm only supporting ePub. HTML-based formats should be quite easy to include and plain text-file support should be doable also, but I have no plans for additional format support right now or at least not during Google Summer of Code.

I am planning to do something like a scrollbar at the bottom of the screen like you mention and maybe also have a widget that shows the current chapter at the top of the screen. These do require some screenspace so I'll have to see how it works out.