Android Service Bell / Client / Host

Want an intranet call button setup where I can have lots of clients and a single host running on tablets in our internal WiFi only. We have a quality control group that needs to get called to check on products before they are shipped. We have about 50 different workstations, each currently with an android tablet in place currently running our WMS. They are a full functioning android galaxy tablet. I'd like to be able to have a call button running on each of the tablets. Just a simple button to call, and a second button to cancel the call. At the HOST level is our QC department. I'd like this HOST tablet to have the core software that keeps a que of each table # that calls, with the ability to assign it to a person and then keep track of basically how long it takes before the call button at the client table is hit as "Finished" At that point, I'd like to have the software run a simple database of the who, what where and time of the transaction for statistical purposes. The closest approximation is in the world restaurant industry as a waiter call. This is common as there is a 433MHZ non-software version that works fine. I have examples listed. On the client tablet, there would be a single button "Request Service." I want this to be very similar to the 433MHZ system used in restaurants. Here's an example of the host board: [login to view URL] Paired with a HOST software that keeps a que and keeps track of time to resolve. [login to view URL] I do have the PC software that these systems use, so you could see what I'm looking for on the host side. If this all works, I'd like a 3rd type of display called a Display board that basically shows the que, and changes as service calls are answered.