the sonoff rf bridge will extend the range of rf remotes already paired with sonoff-rf enabled devices.
So if you have a sonoff rf device paired with a remote, you can add a sonoff rf bridge to your network and use the rf remote button beyond the sonoff rf, rf's range.
the sonoff rf bridge using the out of the box ewelink app enabled firmware will allow you to pair buttons as alarm devices so you can use a ewelink smart scene to turn other non rf devices on or off but not toggle, so to turn on and off you will need to add 2 buttons as alarms..
Using tasmota and some control s/w you have much more options.