UBTECH has introduced a bunch of cool STEM robots lately. Its AstroBot Kit is a Jimu Robot Kit that can be used to build a humanoid, anthropomorphic wheeled vehicle and treaded mobile robot with grab and lift action. You get five servo motors, tank treads and an IR sensor, 2 x 16-color LEDs, and a speaker.
The complete kit has 397 pieces. These robots can be controlled from an app.