the author of this app says:
Dropwords is word-finding puzzle that combines some elements of Scrabble and Boggle, with a dash of Bejeweled. Valid words boost your score and the dwindling timer; used letters disappear and new ones drop down from above. The game offers three dictionaries: 1. Scrabble: contains all the 2-to-8-letter words from the SOWPODS list of Scrabble competition words. This amounts to 114575 words, including both US and UK spellings. Because this is a Scrabble dictionary, proper nouns like "June" or "Rome" are not included. Plurals are included. 2. Webster's: based on the Webster's New International Dictionary, 2nd Edition, this contains 87416 2-to-8-letter words. Includes some proper nouns, but not plurals or Scrabble-specific words (such as my own favourite, "QI"!). I have added certain words that seemed to be missing in error: BOX, HAS, KID, NEAR. 3. Both! The combination of the Scrabble and Webster's dictionaries, comprising 153136 words. This is the dictionary used by default. You can switch dictionary via the game's Options dialog. Have fun!