Can an iphone/android app connect send a request to any server?

I am developing an app where iphone and android phones need to send requests to different servers. Are there any restrictions on this (ie: can we only send via appl开发者_C百科e gateway)?

Yes, you can send requests to any server.

You can absolutely send request to any server. Have a look at NSURLRequest and NSURLConnection if you are interested in communicating through the HTTP protocol.

Anyway, for HTTP communication, I strongly suggest the ASIHTTP framework. It makes everything easier.

Here you can find a general overview of what networking technologies Apple offers.