Excellent application! Just what I needed for my daily commute to work.
Couple of quick suggestions / pieces of feedback:
1) This may have crashed my N900. The N900 rebooted as I was reading a blog post in Grr.
2) Would be nice to navigate directly from opened posts within a folder. Currently, if I am reading and item and want to navigate to the next unread post I have to go up a level into the folder and then click on the next post. Using arrow keys on the keyboard, or swiping the screen would be a nice way to advance to the next unread post.
Anyway, great work! Looking forward to subsequent updates.