My idea is simple but i dont know how to do the result.
I made a free wifi hotspot in our "company" via tplink WR940N. All id like to do now, is to user, that uses our wifi, will be after he connects to our wifi, be redirected on our "example webpage" to show news. And after 30 seconds the internet will be allowed. Our city has also this kind of feature on public city and it is not bad idea.
Not sure if you really understand me.