When you reset the router, you probably have also reset the ssid, and maybe encryption method as well.
However, the Iphone/Ipad is still using the old profile (stored in the device) to connect to the router, this may cause the device unable to connect (or strange behavior, if encryption method has changed).
That's why your friend's laptop can connect to router (internet) cause it recognized a new router and created a new profile.
On the Iphone/Ipad, find out your connection profile, long press and choose "forget this network settings", turn off the wifi, turn wifi on and search your router, once its connecting it will prompt for the WPA key, enter the key and its done.
Perform the same process on every device.