Cake Wallet, and then you can rescan wallet from a date or block height.
Check out the new Polyseeds upgrade for Monero. Cake Wallet adopted it and so are other wallets. Drops down seed words from 25 down to 16 words and you no longer have to worry about remembering your creation date/block height. You'll have to create a new wallet to benefit from it though.
What do you think of the MyMonero on IOS? @SaberhagenTheNameless
I would avoid personally. If I remember correctly they eliminate sync times for you, but they have full insight into your transactions which kind of defeats the purpose of Monero. Double check me on that though I would go with Cake Wallet or Stack Wallet for iOS