iOS Is it possible to change the iphone's default phone app?

[Kpctr]

Hi everyone - Has anyone seen or had any success creating an iPhone app that fundamentally alters the default phone app? I've seen ones like iRetroPhone which is really cool but is a workaround that launches the default phone app. Thanks - really appreciate any guidance here.

 

[admanimal]

If you are talking about a non-jailbroken phone, then it is not possible.

 

[Kpctr]

Thank you - really appreciate the response.