On my smartwatch the swype command to go back is terrible. It’s just not working most of the time, and sometimes it’s basically not possible to perform the back action at all. For this reason I was searching a solution, and I found couple of decent apps that could do the job. This one is, I think, the most complete.
You can set gestures on touchscreen to perform your actions.
Gestures can be simple swypes, double or triple taps, multitouch gestures (do not use them on your smartwatch, because most of them have only a 2point sensitive touch, or even single point touch screen). Then you set the part of the screen that needs to be touched to launch the action. For example you can set a swype right from left border to overwrite the faulty system back command.
The most interesting option is that you can draw your command. For example you can draw a W to launch whatsapp or a D to launch the dialer. Very easy.
Action can be the simplest home, back, recent apps, menu actions. These and a few more are allowed on the free version. The paid version will add multiple actions, as launching apps, shortcuts, and so on. Basically everything can be launched by a single gesture.