Create Android application

Hi, I need an andriod app for restaurant. One device will be installed on each restaurant one device will be given to each delivery boy. Whenever restaurant get a call for food delivery he will press a button on device on his counter (pick now) this order will be sent to a delivery boy and it will ring on delivery boy device for 15 seconds and he has to accept it. if he will not accept, it will be forwarded to other available guy. The guy will accept the order and will see the restaurant name then he wll go to restaurant and take order. after accepting order a proceed button will appear on the delivery boy dvice screen. as he wll pick the order he will press proceed button. after accepting order system will not send order untill that order is not delivered. when he will deliver that order he will press delivered buton and he will be active for the next order. it should calculate that how many orders done, today, this week r this month. but order should be sent in priority like if 3 delivery boys available and 1 of them just deliverd order 2nd one deliverd 15 mints back and 4 orders that day and 3rd one deliverd 20 mints back but deliverd 5 orders that day then systm will send order to 2nd guy bcoz he delivered minimum orders. and 1st one just deliverd order and he is on the way back to restaurant. so this way sytem will keep on processing.