The app should do the following tasks:
1. It should scan a barcode (Which I'll reference as x) using the camera of the smartphone.
2. Then, it should go through a certain column of a google sheet(already containing some details) and check if x is already present in the column :
a. If it already exists, the entire row should be displayed on the app in a well-formatted manner and 2 buttons - one for deleting that row and another for terminating the transaction (and going to the bar code scanning again) should be shown. In case, the delete button is pressed, it should do some small calculations (described later), remove the row and go back to scanning.
b. If it doesn't exist, A new row must be added at the bottom. The details added will be:
i) A specific nick-name for the device which we could enter in the app.
ii) Time of adding the barcode into the sheet
iii) The barcode scanned
iv) Time of re-scans if they exist (in case the bar-code is scanned and the transaction is terminated but the row is not deleted).
3. The entire thing should also be stored in an excel file or a spreadsheet where the columns will not be deleted but the time of deletion from the above sheet will be displayed.
The calculations referred in 2(a) involve calculation of time difference between the time of entry and deletion from the sheet and calculate fine according to a rate 'r' per hour which can be entered in the app as follows: if the difference is less than or equal to a time 't', fine should be zero and if the difference exceeds 4 hours, the fine should be calculated exactly acording to the rate 'r' per hour for the exceeded time. Here 'r' and 't' can be changed in the app.
I am an android developer not just as a freelancer but It is also my profession. I have already done many projects not just in android but In several languages