At our school, we want to make our own attendance application. We would like the teacher to have an app that can read a barcode (from student id card) and send the result to a web server, where we put the timestamp in the database. Our student ID cards only have a barcode for student ID, not a full url. We don't want to start remaking all student ID cards to put a url on it.
We are looking for an app that can 'check in/out' a person with an attached barcode, which can then be sent to our own web server. We like to be in full control and have just the data sent, and decide for ourselves what we do with it. We don't want complete integrated solutions where our data is on a remote server somewhere owned by someone else.
I have no experience with app creation, but I know databases, PHP and Java.
Preferably a free or low cost (one-time fee) app, available on Android and iOS. I doubt a website can read a barcode from the phone camera but well, surprise me.