At least with the PHP REST libraries, the functions are fairly obvious. Take a look at space.php and you should be able to figure out which function to use. Something like:
$s = new Space($consumer,$secret);
$friends = $s->friends($user);
As far as your application needing to be accepted, it's not required. Your application must be "friends" with a user in order to access their information but if you're not live, you have to add others as a friend of the app to allow them to install it anyway.