Hello,
I am using User Manager 4.11. Currently i have got my hotspot completely set up and everything is working fine. I want to add another feature into it, which is that i want to give free internet to the user for 30 mins when he connects to the hotspot for the first time. Is there any way to do that??

I was thinking to do it through MAC, whenever someone connects to hotspot then login page is bypassed and he is allowed to user internet for 30 mins. After that time his MAC would be added in some sort of list that keeps track of all the users who have used their 30 mins. When he connects again to the hotspot, his MAC would be matched in the list and he won't be able to use internet for free. (I know if he has got 5 laptops then he could use it for 5*30 mins but that does not matters to me).

Any advise???

Turn on the 'trial' login method. That's exactly what it is made for.

But isn't that for specific MAC address. I will have to enter MAC address myself??

Are you trying to only offer this service to a few select users? If it's for all users, the trial feature tracks who has used a trial before by MAC address, and doesn't let them use it again until a time period you specify has passed.