If you enjoy word games, you'll love Scramboni. It's an anagram game, with an online competitive twist.
The gameplay is simple. Every game is 20 rounds, 20 seconds each. You are presented with a jumble of letters, and you have to solve the anagram by tapping the letters in the right order as fast as you can. Motivation for being super quick is that you are competing with other players. You can't choose your opposition, it's just whoever's online playing.
There are four skill levels, and you have to earn points by playing the game to level up. so, until you have enough points you are stuck on level one. The presentation is pretty basic, but it does the job, and the letters are big enough for the touch control to work well.
The only issue is that you are stuck to playing the game at a set pace - there is no one player mode. However, the online mode is so compelling, you're unlikely to care!
Clear out your diary, and let Scramboni eat away your time.