If you are having issues joining the WiFi on an iOS device it's usually because it's not automatically opening the gateway page. To manually open the page, do the following on your iOS device:
- Connect to the WiFi (attwifi, hhonors, etc.)
- Enter the address "1.1.1.1" in a web browser (Safari, et al.)
- Complete the gateway page sign-in
Once you've gone through the gateway page, you should be able to use the WiFi on your iOS device without issue.