Its definitely the very best Crossword app that Ive found in the 4 years that Ive had an iPad, iPhone, etc. much better than the New York Times crossword app; which is a paid app. The only improvement that I would like to see is the addition of more of the more difficult/bigger puzzles like the one they do carry "Premier Crosswords". The easier puzzles they have hear tend to use the same clues/answers over & over so that there is very little challenge for your brain.
Oh & I do have to agree with THROO7 in that the puzzles dont sync between my several devices, so that if I just completed one on my iPad Air2 & then perhaps happen to be bored waiting somewhere & open it on my iPhone or iPad Mini, it will offer that puzzle as one never started, so thats kind of a bummer
Addendum- Mar 2016 - They still have not fixed the problem with the puzzles not syncing between devices.
phy3joy about Crosswords Classic, v2.74