First of all, thank you for developing and maintaining such a wonderful and practical tool - and plugin!
I think it will be easier to explain my issue and, then, suggest how I think it could be solved.
I am currently lecturing big classes (up to 120 students), so I do not want to spend time calling their names to manually fill the attendance record, I'd like it to be automatic. Currently, students self-record their attendance through their mobile phones with the password that I provide at the end of the class. However, I presume many students that missed the lecture get the password via whatsapp and register their attendance (even if I restrict the IPs for wireless access, they can be anywhere in the university and register their attendance). So, I would like to make it more difficult - ideally impossible - for them to cheat and self-register.
I thought that instead of using a simple password, a random QR code could be projected at the end of the lecture through the lecturers attendance activity. Students should scan the QR code (maybe through their attendance activity) to get the attendance. The QR code would be randomly changed every 2 or 3 seconds so that students do not have time to send it to others. If they miss the code, they just need to keep trying till they get the code in time.
This is just an idea - I am open to other sugestions!
Thank you very much,