The classic game UPWORDS from indie developers at Lonely Star Software.

UPWORDS adds another dimension to crossword board games. Build words by playing letters across, down and stacked atop existing letters. This unique 3-dimensional game play allows you to change existing words into new words. Score points for each letter tile in your word and every letter tile under your word. The higher you the stack, the higher you score. Build words, stack letters, score high and have fun!