Connect to strongest known network first

I have a bunch of WIFI networks that I use near my home. In most places, I can see 3-5 of them, but only the one I'm closest to is really strong enough to be useful. But knetworkmanager usually chooses to connect to one of the weaker ones, and I have to manually tell it to connect to the strongest one. It would be good for this to be automatic. Also, it would be good if a connection dropped, for it to try to connect to the next strongest network.

A process like this would be good:

1. Check the strength of all known networks in the area.
2. Connect to the strongest one.
3. If the connection strength drops below 30% (customisable), see if there are stronger known networks available. Go to step 2.