android apps that alter normal phone operations
<p>so i was wondering if its possible to for an application that i would write to be constantly running in the background and alter regular phone operations.  For example this could be something like as soon as you receive a text from anyone you forward it automatically to another number.  Is something like this at all possible?</p>

<p>Just to be clear I don't want to solve that particular problem through some other means, just want to know if apps can accomplish that.</p>

<p>Also if that is possible is it possible for an app that i write to alter more immediate and instant things, like an incoming call.  </p>

<p>thanks all for reading this, and hopefully a  helpful response :)</p>
