As I mentioned earlier I threw this together in an evening. It's more of a proof of concept than anything. My first attempt was to use a coin cell battery for power but ESP8266's don't like 3.0 volts. I had to find another power source so I dug a battery out of one the minicopters I had. The ESP likes 3.7 Volts just fine. The combination of the small gear wheels and the high speed of the motors means it's very zippy. With the gpio lines as output I can use pwm to make it go whatever speed I want. The limited GPIO of the 01 modules means that there is no room for inputs. A better choice would be a 07 or 12 module. That could give you 9 GPIO which means you could 4 bits with a H-bridge on the motors to get full control of direction and you would still have 5 gpio plus an ADC for Inputs. As it is it can only go forward and turn left and right.

Once I finish the drivers I will have to start the software. Basic software could serve up a web page and use buttons with links to give the signals for output. Not sure what kind of lag I will encounter though. I could make it a telnet server and use single character codes to drive it left,right or forward. A enhancement to this would be to allow it to load up codes and then execute a sequence. It should be fun to play with.