booster signals?

I live on a rural area and I download this app called open signal and it showed the nearest T-Mobile Tower. Doesn't say the distance but it shows you like a map from your location to the tower and it seems is about 5 or 6 miles away. I live in a 2nd floor apartment on a 3 floor building. I have my home WiFi I purchase from T-Mobile I believe the device is called a gateway. I get around 2 or 3 bars with 15mb download and 5 mb upload. I believe the gateway has a sim card like phones do so I'm assuming it uses Internet without the calls so I'm assuming that a cellphone booster repeater should work to amplify the signal from the tower. But before but it I want to know if this could work.