There is no app that can boost your WiFi signal in any direct way. Some apps may be claiming so, but most of these apps are just package managers. When you send something across the internet it's sent as packages and is routed through many locations. Package managers prioritize certain packages on your system and deliver those packages faster and more clean to their destination. A good example is package managers made for gaming, they optimize traffic that online games require and deliver a better experience to the player. However, there is a good reason why all people just don't use these package manager apps because there is almost nothing to gain from them. In my experience, I wouldn't try downloading any app to boost my WiFi or internet speed.