I recommend jailbreaking the iPhone 4S and installing TetherMe, it will install with it, TetherMe APN Editing which will allow you to edit the Cellular Data Network settings, so you can get Data, MMS, and Personal Hotspot working as well.
The unlockit.co.nz APN services does not install MMS settings (as by default, it's restricted by Apple) so it's better to do it through this way, and before you input your settings, make sure to uninstall the profile installed by unlockit.co.nz as it will interfere with the settings.
Verizon iPhone 5 32GB black unlocked
PagePlus iPhone 5 16GB black unlocked
T-Mobile Samsung Galaxy Note 2 16GB Titanium
T-Mobile Samsung Galaxy Note 2 16GB Titanium (2nd)
T-Mobile Samsung Galaxy S3 white (cracked)
AT&T iPhone 4S 16GB white (cracked)
PagePlus iPhone 4 16GB
MetroPCS iPhone 4 16GB (cracked, non-usable)
AT&T iPad 3 16GB LTE (somewhere in the house)
iPad mini 32GB white
iPod touch 5 32GB blue
iPod touch 4 8GB white (missing display, non-usable)
Blackberry Bold 9700 AT&T