The Revo Tri Skate Dolly, Smartphone Mount, and Articulating Arm Kit from B&H includes a 3-wheel tabletop dolly, a smartphone mount, and an articulating arm that'll let you attach the smartphone mount on the dolly in various pan/tilt positions. The smartphone mount is compatible with iPhone, Android, and BlackBerry phones and is expandable to support any device up to 2.75" wide (when held right-side up). Its design allows you to insert your phone along with any protective case you may have it in.
The dolly supports up to three articulating arms so you can also mount lights, monitors, mics, and other accessories. You can also attach the smartphone mount via an optional ball head or tripod head to a 1/4" screw in the center of the dolly. A 1/4"-to-3/8" screw adapter is included with the dolly for attaching tripod heads.
The dolly supports up to 40 lb of gear and can be used on a tabletop or any other flat surface. It moves fluidly in straight lines, curved lines, wide circles, and tight 360° spins, according to how you align its wheels along scale marks by each wheel. The scale marks are usefully located on the top surface of the dolly instead of the underside, enabling you to align the wheels without flipping the dolly and all attached equipment over.
The articulating arm features a single knob that tightens the center axis and the end joints all into position at once. The arm has a 1/4" screw on each end and comes with a shoe mount that can be screwed to either end.