What is a "signal booster". It depends on the country you are in but most these type of devices are illegal so you have to be very careful that the company selling them is not trying to scam you.
There are some sold by the cell phone companies and those might be a option.
The problem is the cell phone company has purchased the right to transmit on certain frequencies and nobody else is allowed to use them. So any device not sold to by the holder to the license....ie the cell phone company .... can not transmit on their radio frequencies.
Now there are some fancy passive antenna things that might be allowed but very technically most third party antenna are also not allowed.
I would not get my hopes up on finding some magic box. Most times the cell companies offer small routers that you can put on the roof that do the same thing as your phone. It would then be run inside via a ethernet cable and you would use a normal wifi router to allow you to connect your devices. This is more sold to a business that a home users but you never know what they offer.