ElyGo is a complete Go game app (Igo Baduk Weiqi) for enthusiasts.

A free version is available here : http://goo.gl/wynXit

Features :

- A database of 20000 Pro games
- More than 500 Tsumego problems with answers as well as bad variations
- Play and observe games online on IGS
- Import your own tsumego problems
- Import your own game database
- SGF Editor to review and edit games
- Play against the computer (GnuGo 3.8)
- Loads Kogo's Joseki Dictionary
- Pattern search
- Choose your color in problems (black white or random) and change several other settings (almost anything is configurable)

Features to come soon :

- More pro games