So you would like to use your smartphone like a real camera? The ShutterGrip has you covered. It attaches to your smartphone, with or without a case and lets you control it more conveniently. It comes with a tripod screw, lanyard hole, and non-slip grip.
ShutterGrip has a Bluetooth shutter button, so you can take selfies, videos, and everything else. Works with iOS and Android devices. More info is available here.