I play WW2 Wings of Duty, by the way. I've had it ever since the game first came out iOS, on July 10, 2015. So far, it has been doing well, but issues about the game pop up sometimes. I like how to game has incredibly detailed cockpits (for a mobile game, and it seems like it has the best cockpit for a mobile game). I've never seen any other WW2 game as good as this on iOS. If you're wondering why you have to spend real money to get gold currency for new planes, it's because the developers need funds to develop the game.
The best plane to fly in the game is the F6F-5 Hellcat, as of version 1.0.5. It has a lot of engine power, climbs quite well, and is pretty good in a low-moderate speed turn (in the game). With it, I've killed Zeroes almost every time I got into a turn fight with them.
Although I'm not the dev, I know some stuff that is coming to this game in future updates.
I can't wait for the European Theatre to be added. There will be a Battle of Britain map and a Germany map, I believe.
Right now, the current aircraft in the game:
P-35, P-40, P-39, P-38, SBD, F4F, F6F-3, F6F-5, Hudson, B-25
Upcoming aircraft:
Bf 109, Spitfire, P-47D, P-47N, P-51D, TBF Avenger, B-26 Marauder, A-26B Invader, A-26C Invader, F4U-1 Corsair, F4U-1A Corsair (can be upgraded to F4U-4 Corsair via engine upgrade).