Android & Ios Scan Network For Raspberry Pi?

I want my Android and iOS (Swift to be specific) apps to connect to the Raspberry Pi in the network. Of course I can set a fix IP for the Pi and hardcode the IP to the apps, but I

Solution 1:

If you are connected over Wifi(Access Point) then you can discover devices using SSDP protocol.which does multicast at 1900 port and whoever has joined to particular group will receive and can respond back with information.It can be implemented both side App as well as Pi.