Worbble: (iOS, Android) ` 55
Worbble is where the word meets bubble and the aim is to make words from alphabets that appear on the bubbles. In the Word Mode, the player gets limited time to burst bubbles and make as many words as possible. Quiz mode throws a question to which one has to find the answer within a limited time. The question can be anything from general knowledge to mathematics. There are options to skip the question or use the hint. The game has an underwater theme where letters appear in bubbles. Sadly, it is not free.