But seriously... it's free, use it if you want, don't if you don't want. I needed a small project to get to grips with android development and this certainly helped :)
p.s. If you are wondering what the symbols are before the book titles thats a reference for myself it will change over time.
- key -
no symbol = I have first edition
~~ = I have a copy of the book but not first edition
---- = I don't have this book