I know I can switch polarity in a 12vDC Geared Motor with a DPDT Switch and crossing the legs with positive and negative.
I would like to do it electronically. More specific I would like to add it to my moteino project so I can send a signal from the controller to the device and have the motor reverse. I am somewhat worried about relays as if things go south with the relay we release the blue smoke. I see some electronic motor regulators but so far they look to be designed for stepper motors and I all want to do is all on backward or forward.
So has anybody used any prebuild DPDT switches or prebuild motor drivers that can keep this project simple?
Look at an H-Bridge circuit. There are plenty of pre-built H-Bridge boards out there that would probably work for you.