For cars, I've heard of LLumar used as window tint.
Do jet aircraft use window tint? If so, what type of window tint do they use?
Yes, airplanes (all types including jets) can use window tints.
Tints for airplanes are with enhanced protection from UVA radiation. UVA exposure can increase the risk of skin cancer and will damage most organic materials. Its intensity increases about 5% with every 1000 feet of altitude. Unlike car tints, airplane tints need to block the additional exposure to UVA.
Solar Energy Control
Tints also block near-infrared radiation which results in lesser interior heat.