Wifi Switcher

If you've got several available WiFi networks of varying signal strengths within connection distance, you might frequently end up automatically connecting to one with a weaker signal than is ideal. To keep you from constantly having to switch between them manually, there's the Wifi Switcher app.

This tool can detect all the available WiFi networks around you and connect to the one with the best signal. If for some reason the signal quality drops and is beaten out by another available network, the network will be auto-swapped to optimize your connection speed.

Although there's a paid version that lets you set the minimum threshold of signal strength at which to make the auto-swap, this basic edition is precise enough to use without missing out on much. You can also specify which networks you prefer from amongst all the available ones that are detected.