Automating salt/pepper flow using Arduino

I want a hardware designer to create a hardware circuit that controls the flow of salt and pepper. The typical scenario is like this: 1. Circuit gets a command from external (Bluetooth) source to let the salt or pepper flow for a specific amount of time. 2. Circuit opens up the actuator (solenoid? to be discussed) to let salt or pepper fall by the effect of gravity for a specific amount of time. Salt or pepper could be saved in some sort of a pipe or a box (to be discussed) 3. Circuit closes the actuator to stop the flow after a certain time. The circuit has to be as small as possible. Using Arduino is recommended but not a must. If you have some other ideas, please let me know. The actuator -I mean that thing that will control the flow of the salt/pepper- has to be small and cheap. I will choose you for this project if: 1. You send me a private message indicating which board you will use for prototyping (Arduino Uno, ... etc), bluetooth shield, and the type of the actuator you will use, its price and a link to where to buy online. 2. We discuss the timeline and some other more details. 3. Once we agree, I grant you the project. Deliverables: 1. Initial design of the circuit, different components, prices and online links to buy them online. 10% of cost transferred. 2. A video showing the first prototype working with no bluetooth commands (Just internal commands) showing that the circuit controls the flow of salt/pepper. 30% of cost transferred. 3. A video showing the circuit controlled via bluetooth shield. 20% of cost transferred. 4. Full documentation of the project. (hardware full design, code and description of work) 40% of the cost transferred. 5. Hardware cost reimbursement (If the freelancer would like to ship it to me)