Lakeview Boat Launch

I own a marina that launches boats daily. I am trying to create an app or program that can be used on 6 iPads on our side and send text messages to the customers’ phones. One iPad would need to keep or at least access a database. I have included a diagram of the way I would like things to flow. I will have a Wi-Fi network through the whole campground and marina area that the iPads will be able to access. To start with the employee, iPad would give the option to launch or load. In the launch mode it allows the user to assign the next number to be used. Between 1 and 200. After doing that it would take them to a screen that would ask for the customers phone number. After entering this number, it would need to send a text to the customer letting them know their number and giving them a button to press to send a message to get their boat out of the water. The employee iPad would get a go/no go screen letting them know the phone number and trailer number. If the customer does not receive the message the employee would be able to look at the information to see if something is wrong and need to go back to the screen to make the correction and then return. If the customer receives the text message and the info is right, it will then enter the info into a database at the store to let us know the phone number and trailer number that is on the water. Only the store iPad would be able to access the whole data base. On the loading side when the customer would press the link on their phone it would alert all iPads that a boat was ready to come out with the number on the screen. The iPad at the store would be able to see the whole list and the order that they would need to come out. The employee iPad would only have the next number. When the employee is grabbing the trailer, they would press the number on the screen to let the store know that the trailer has been hooked onto, and it would let the customer know that the trailer is heading to the water. It would then let the other iPads know the number of the next boat if more than one boat was ready to come out. When the boat is loaded and coming out of the water, they would need to press the boat loaded button. If the boat was loaded it will return the number to not in use and remove the phone number and the trailer number from the active database. It also needs to close the ability of the phone to be able to ask to be loaded out of the water. If the boat isn’t loaded it needs to be put back into the list to be loaded.