RSSI program

[AElkenawy]

Hello
I need to make a program to measure special wifi MAC addresses strength with my mobile phone , but i am totally beginner to javascript and i don't know where to start so what are steps ?? so if anyone have an already-made example this would be awesome :)

I also used construct 2 (Game engine compatible with cordova .. etc) to make such programs , but i can't find a plugin for it and don't know (if possible) how to convert the src , www , .... files to the C2 files , so if anyone know about that would be great.
Thanks in advance