If you see a 403 error page in your android / iphone application that means your application is not able to send http or useragent (UA) string request because mod_security is blocking its request.
Best way to fix this 403 error is-
You can click here to read about sending information to applications using user agent (UA) strings.
Shows setup http useragent using android-
https://developer.android.com/reference/android/webkit/WebSettings.html#getUserAgentString
Shows setup http useragent using iphone-
https://stackoverflow.com/questions/5155479/how-do-i-check-if-the-useragent-is-an-ipad-or-iphone