Override phone app launched from mobile Safari tel: link on iOS?

Question

Is it possible to have an iOS native app register for the tel: url scheme so that mobile Safari will launch it in response to HTML tel: links rather than the built-in Phone application? Ie to override the built-in Phone app ?

Answer 1

No, at least not surely. I remember Apple docs saying that if two app registers the same URL scheme, then the behavior is unspecified when using that URL scheme. You can do this, however, with a MobileSubstrate plugin (if jailbreaking is an option), which hooks into SpringBoard and opens a different application when that particular URL scheme is encountered.