Hugoban - Go, Weiqi, Igo 1.2.1
the author of this app says:
Study Go on your phone! The ancient game of Go, also known as Weiqi, Igo or Baduk. Study hundreds of built-in pro games. Study hundreds of built-in tsumego (life and death) problems. Guess next move with hotness indicator. Save and Load games from the internet. Become stronger!