nit: I found the sentence "you found the nth highest scoring word" a little confusing since there can be >n words with a higher score (e.g. there could be 6 words scoring 12 and you found the 2nd highest scoring word with a score of 11).
You could just drop the sentence since the top scoring words are shown below.
Other nits:
- Gray the submit button until the word is valid, otherwise it's unclear why clicking on the submit button doesn't do anything.
- If you are trying to find a word and switch tabs, things get reset when you come back.
- If you place tiles forming a word, a space, random tiles: you can submit the first set of letters. IMHO, it shouldn't let you submit if you have spaces between tiles.
- Display the best word I have found so far, but let me keep trying other tiles.
nit: I found the sentence "you found the nth highest scoring word" a little confusing since there can be >n words with a higher score (e.g. there could be 6 words scoring 12 and you found the 2nd highest scoring word with a score of 11).