I allways wanted to build a smartwatch by myself, and also wanted to get in touch with android programming.
Because I did not know what were the main problems (getting it small enough, or the software side on the smartphone or on the mikrocontroller) I decided to build it for my motorcycle handlebar first.
I decided to do so because of the following advantages: I do not have to worry about the power consumption since I can connect the device to the board power supply, and the size of the device is not as crucial as if it were something to wear on your wrist.

The app for the android side allready exists and I also tested the first prototypes on my motorcycle. The next steps are to shrink the device (prio 1) and refine the android app. (prio 2)

Hardware:
The device is using an Atmega8, programmed in C, display is an ks0108

Oh and by the way:
I will publish all files needed to build the device and use it: Android App source code, files for the PCB, mikrocontroller sourcecode.