I was so excited to find this utility since it allowed me to control how and which access points my android device will select when the signal gets less than optimal.
First thing I like about this application is that it identifies the signal strength, authentication type of the networks you can hear. Here's the Google Play Link.
The second thing is the cool part, but consists of 3 components:
Switch Signal Threshold is where you set the signal value at which your android device goes off to find a better signal