Xtrem Bots Mazzy is a robot for young(er) kids that involves assembly from parts (plastic parts, screwing together with screws, and fitting together with clips).

It also has an iOS / Android app that can be used as a radio control, or to program the robot over Bluetooth with a visual programming tool. It also has some buttons on the front that can control its motors, but that's a bit of a sad way to work with this.

Sort of a cheaper alternative to the BBC micro bot / micro.bot robots or the Arduino-based robots, with simpler features but not as capable.

You can build one of two different robots - an "android" or a four wheel rover vehicle. It also has a line following thingymajig.

This has been assembled once, so parts have been taken out of the flat trays), and then disassembled again so it's almost as it was out of the box including all parts, screwdriver, and instructions, but I left the wheel assemblies (two pieces that clip together) assembled as they were a mega pain to get assembled.

Would be lots of fun for anywhere between 6 and 10 that likes robots, lego, meccano, any of those sort of things, and has a vague interest in "programming" or remote control.

Requires 4x AA batteries, works well with Eneloop or Ikea Ladda NiMH rechargables.