[avinoth]

Without specific hardware to it, I don't think so.

But you can always use your Wi-Fi router to detect the unique number of devices connected but that still rules out people connected through data plans.

Payrollhero has an attendance management app for office, but not for events as such.

If you don't mind using a separate hardware density[0] came out recently and looks very promising.

[0] - http://www.density.io

[udswagz]

but it would not be accurate, i was thinking if there was a way that the attendees could actually check it and mark themselves as present to the event or place without having to be counted by someone, all the organiser has to do is sit and watch people check in.