My iPhone 4s has a Wi-Fi signal, but several apps won't connect. Why?

I'm at my university on their Wi-Fi. I show a signal but nothing will connect. I've found this happens on a lot of publicly-accessible, "free" Wi-Fi, like in airports. What's going on and why can't I use it?

Most of the time, if you are using public networks that are 'free wi-fi', you will need to accomplish an additional log in by starting your internet browser to authenticate your connection to the network.

Yep, open a browser. It will likely redirect to 1.1.1.1 and either have you accept some terms and conditions or require a logon. One you've done that the apps can connect

Hi
It happens to me sometimes even with my Wi-Fi at home at that point I go to settings and there on off Wi-Fi which actually works. Try this may be this helps