Launch an app from within another (iPhone)

Question

Is it possible to launch any arbitrary iPhone application from within another app?, For example in my application if I want the user to push a button and launch right into the Phone app (close the current app, open the Phone app).

would this be possible? I know this can be done for making phone calls with the tel URL link, but I want to instead just have the Phone app launch without dialing any specific number.

Answer 1

As Kevin points out, URL Schemes are the only way to communicate between apps. So, no, it's not possible to launch arbitrary apps.

But, it is possible to launch any app that registers a URL Scheme, whether its Apple's, yours, or another developer's. The docs are here:

Communicating with Other Applications

As for launching the phone, looks like your tel: link needs to have least three digits before the phone will launch. So you can't just drop into the app w/o dialing a number.