GoPro is not the only company selling a foldable drone-- DJI has a similar product, the Mavic Pro, a small and slim drone promising many of the advanced features from the larger DJI Phantom drones.
The Mavic Pro does not exactly qualify as palm-size, but is small enough to fit in a backpack or purse when folded. Sensors on the front and bottom provide obstacle avoidance, subject tracking, autonomous landing and indoor stability, while a 12MP camera sensor shoots 4K video at 30fps and HD video at 96fps.
DJI claims the battery allows for 27 minutes of flight on a single charge, and the drone's top speed is around 65km per hour (in comparison the top speed of the larger Phantom 4 is 72km/h).
Control comes through a miniature version of the DJI controller featuring a small display showing basic telemetry information such as height, speed, distance and orientation. One can also control the drone solely with a smartphone and companion app, as well as clip the phone on the controller to add a live camera view touchscreen controls.
A variety of flight modes is included, such as Sport Mode (allows the drone to fly faster) and TapFly (tap on the screen to tell the drone where to fly).
The Mavic Pro should ship by around mid-October 2016.