Having been in competitions when I was younger, I downloaded this app for amusement. I found that the etymology is lacking for over a majority of the words. I wouldnt ask any more on that part, (although a thorough guide on language patterns, prefixes, suffixes, etc., would be perfect) considering that its a free app. It would also be nice if there was an option to the randomize the words. But overall, I was pleasantly surprised with the quality of the app.
"Queen Bee" about Spell + Friends by Tap To Learn, v2.7