Counting (inventory) of products by barcode for android

I need to create an android application that, through a barcode reader (keyboard collect mode), allows me to register the count of items in a warehouse, registering datetime, physical address code, barcode. Registration will be offline at the local bank. Business rules 1) When starting the app it should show a menu: 1.1) Start Address Counting 1.2) Finish Address 1.3) Count Items 1.4) Receive product file 1.5) Transmit registered data 1.6) Complete application in option 1.1 the application must control when the address is open or not so warn and not allow having 2 addresses open. in option 1.2, it closes the previously opened address. So it will only be possible to close something previously opened. in option 1.3, the system shows the open address and is in a loop receiving the bar code and showing how many items have already been process into this address. It can be only enter here if you have an address previously opened. still in option 1.3, there must be a button available to exit the counting screen. that button never gets focus. The logic is to receive the barcode and record it and already clearing the field for the next record. each counted item must have a sound beep confirming that the item exists in the product register and printing on the screen the description a und of measurement (received from the text file) of each beeped item. Continuing with option 1.3, each item entered must have a corresponding record in the registration previously received. if not, there must be a sound error beep informing the error (and such a record should not be made). in option 1.4, a product file will be imported (CSV text format) with the fields product description, barcode, internal code, unit of measure in option 1.5 the recorded count will be transmitted (posted) using TXT format to an API's endpoint. The information that must be included are datetime, address (registered on screen 1.1), bar code, internal code. in option 1.6 the system is closed/terminated. The final product of the delivery of this development service must contain a tested functional application, together with their sources, with the specification of the technology used enclosed (preferably for us is Java with eclipse or android studio)