On ios it is better to use the common controls. In this problem the
UIAlertView or ActionSheet is the right solution for ios 7. But for ios 8 and later use the UIAlertViewController. So you need to implement both, if you cant avoid the old ios 7. It is common technique to implement both ways and choose on the OS of the device at runtime.
Take also a look at this nice
DropdownMenu at Github.