Here is a smartphone camera rig that lets you use your iPhone 7 to capture more professional videos. The Melamount iPhone 7 Stabilizer Pro Rig supports horizontal and vertical videos. It has swing-out handles, threaded lens mount, shoe-mounts, bubble level, and tripod socket to accommodate all your favorite video gear.
You can attach lenses, video lights, microphones, and other gear to this rig. Costs under $40 at this time.