I am assuming you are looking for one to obtain an internet signal near you but that is weak, right? The boosters to increase phone service are much more expensive than just boosting an internet signal from a store or campground.
I use this one occasionally when I have campground internet but cannot use my Verizon hotspots. I gave my first one to my son and his wife for their trailer and bought another for myself. I do not use it often, but you just plug it into your USB port and that's it. No setup at all:
https://www.amazon.com/Crane-Super-USB-Wifi-Antenna/dp/B004UR72IMWithout it, I will get maybe one or two bars signal. With it, it will jump to 4-5, and a lot of other signals will appear that I could not see before. Last time I used it was a month ago at Willow Beach Marina which has no cell service, but does provide internet free.
I have also used it sitting in my vehicle outside of a McDonald's or a big box store. Penney's, Sear's, and Macy's often offer free internet and it is much more comfortable to be sitting outside than having to go into their stores. I hang it in my window, but there is also a suction cup.