Here is a Smartphone Spy Lens that lets you take photos at a 90-degree angle, so you can hold your phone and capture shots without raising any suspicion or disturbing your subject. The attachment twists 360 degrees, so you can use any surface as a tripod for your phone camera.
This Spy Lens is compatible with iOS and Android devices. It attaches to your phone by a magnetic ring and doesn’t damage your phone. Not too expensive either.