https://www.yutopian.com/yutop/cat?product=ECFME&category=Ef
Best tool to learn Fuseki with lessons on basics, and 16 most common fuseki including the Shusaku Fuseki, Cosmic Style, Nirensen, Kobayashi Style, Chinese Fuseki, etc.
http://remi.coulom.free.fr/CrazyStone/
Currently one of the strongest go playing engines. Available for PC, iPhone and iPad.
http://webpages.charter.net/suewilcox/ego.htm
eGo
by Bruce Wilcox. It plays with nine different personalities.
http://www.smartgo.com/touch.htm
Over 10,000 professional games and 2000 Go problems in your pocket. Can also be used to record your own games.
http://www.moyogo.com
Automatic, instant Go pattern expert & relational Go game database