Implementing google places autocomplete API in iOS
Check out https://github.com/spoletto/SPGooglePlacesAutocomplete
It's an objective-c wrapper for the Google Places Autocomplete API.
Good Luck!
And here's a Swift version :)
https://github.com/watsonbox/ios_google_places_autocomplete
And another alternative: https://github.com/TarasRoshko/TRAutocompleteView
Can be binded to any existing UITextField in single line of code. Supports customization, configurable. Should be good pick for UITextFields, handles resizing and orientation automatically. I've created it because all existing solutions do not provide simple drop down list for text field, but whole separate views, or even "placeholder text suggestion", sometimes even without a possibility to actually autocomplete.