There are some great free book apps out there. Classics To Go is a good one to start with :) but do a search for book apps and a bunch should come up. There is even a free audiobook app to listen to classic literature.
I like Feedly because it helps me keep the blogs and websites I am following organized. It's a newsreader and makes my life so much easier. I am a writer and I usually start my day by scanning all news websites every morning. Helps a lot to have my feeds in one app. It's available on Google Chrome.
For offline apps, Fissionlink developed an app that is more than a loyalty rewards program. It is actually developed by my friend and you use a card to get your points. Sort of like an ordinary loyalty rewards card but you can use your social network, play games, and redeem prizes from the accumulated points. :D He's developing a mobile app for it. Genius, that person is.
Pulse - keep track of your favourite blogs (free) YouTube - sign in access to your account and also watch all the YouTube videos (free) Viber - call any viber user free via 3G, without the trouble of using a user login every time, it even syncs the viber users from your contact,because it uses your mob no. to identify you(free) Snapseed - best app to edit and create awesome effects to your photos (free) Photosynth - best app to capture panorama and share them on bing maps (free)