Use this app - MY SPEED.
It will show you:
- your current speed in km/h and m/s,
- your current GPS position,
- your actual altitude above sea level.
Copy these data and send to your friends to find you more easily.
Do not forget to turn on the GPS :) in your android device.
The permission which uses application are required for its proper action. These data are not sent to the author of the program.