I understood when people were getting free tethering but all the new plans have that. And...I don't think you need to replace the kernel for that...just root is needed I think.
Myself: 2014 Kia Soul+, LG G3, Motorola Droid Razr M, Nexus 7 (2013), multiple Google TVs
Wife and Kids: Motorola Moto X, iPad 4th Gen, HTC Droid DNA, Galaxy Tab 3 (7"), iPhone 4S, Nexus 7 (2013)
Retired: HTC Droid DNA, Galaxy Nexus, Thunderbolt, Droid Pro, Fascinate, Motorola Droid 1, 3 & 4, Transformer TF101, Galaxy Tab (7" WiFi), Archos 70