Lutron Caseta has some good documentation on this. You would need to replace one of your existing switches with their product, and then you can place remotes anywhere you like.
For a three or four way topology, if you want to keep your existing switches, you'll need to use the PD-10NXD, and definitely wire up the neutral.
That is a dimmer. There might be a switch that's compatible with 3/4 way, but I've only used the dimmer.
Lutron Caseta has some good documentation on this. You would need to replace one of your existing switches with their product, and then you can place remotes anywhere you like.
For a three or four way topology, if you want to keep your existing switches, you'll need to use the PD-10NXD, and definitely wire up the neutral.
That is a dimmer. There might be a switch that's compatible with 3/4 way, but I've only used the dimmer.