Maybe you have problems with your Wi-Fi network at home, at work or anywhere else. Phone does not reconnect to another known network even when it has much better signal.
Wi-Fly solves your problem forever. All you need to do is to pair those Wi-Fi networks inside the application and it will take care of the rest. Once stronger network appears it will force your phone to switch to it.
It's required that SSIDs (names of Wi-Fi) must be different while you pair them.