go to ----> https://bitcoin.org/en/wallets/mobile/ios/ and download wallets from that site only "After reading the advantages and disadvantages of each wallet."

Based on my experience I recommend that:
 
  1. greenaddress: they support SegWit addresses "P2SH/started with 3", They had a problem sending to addresses starting with "bc1" and solved in the last update.
  2. edgewallet: I did not use it, but I know they support SegWit addresses
  3. use web wallet [I do not recommend it]: You can try any web wallet and access it using your browser