Conquist
Risk for iPad, yummi
Download
LUDO Family Board Game
Best Ludo game out there.
Download
Blokus HD
Mind bender game, it has some decent computer players as well.
Download
Fluke HD
Nice simple board game. Good for playing with kids. Could use a few more interactive elements.
Strategery
Maybe not really a board game, but kinda. And it is a great game so it makes the list.