mobile app: speed gun 503$

hi,

i iam looking for an app i can use in a mobile that i install onto my letter box and measure the velocity of passing cars.

i have awarded someone who didnt accept the award afterwards and wanted a paypal guarantee-service, probably a scammer, so i repost again here. i wrote a contract that includes every detail (i hope), with milestones and sum. this deal is non-negotiable, if you demand other sums, please dont answer to me!
pls dont just bid, you would need to sign the contract! your offer must be 200 for the first part, which can be subdivided into 2-3 milestones as you wish, and then we go from there.