Edit: Corrected version below
var appSought="com.smartphoneremote.androidscriptfree";
function OnStart()
{
lay = app.CreateLayout( "Linear", "fillxy" );
app.AddLayout( lay );
appList = app.GetActivities();
ret = appList.filter(function(a){
return(a.packageName==appSought);
});
a = ret[0];
img = app.CreateImage( a.packageName+"/"+a.className,512,-1,"Icon,px" );
lay.AddChild( img );
img.SetOnTouchUp( img_OnTouchUp );
}
function img_OnTouchUp()
{
img.Save( "/sdcard/thisIcon.png" );
app.ShowPopup( "Saved" );
}