The Phillips Hue line on smart Bulbs are interesting. You must purchase a HUB to use their full capabilites, but they have a lot of functionality once your spend the money on the setup. The hub needs to be plugged into your home network but once done can turn lights on and off automatically based on the time of day. The bulbs themselves act as regular light bulb. Turn on the light switch and the bulb comes on at standard brightness. Turn off the light switch and the bulb goes dark since it is without power.
There are apps for the phones, as well as wireless remotes. The phillips Tap is one that does not require batteries and can be stuck to a wall to provide remote on/ off and dimming based on programs that are set in the hub to interpret its four switches. There are battery powered remotes as well.
You can’t control a light that has been switched off by a regular wall switch, but once on you can turn lights on and off or dim and brighten them as you choose.
One of the big andvantages is that there are no changes needed to the house wiring.
I have dabbled with Insteon and X10 lighting control and hate digging into the wall boxes to replace the switches. So lately I have been using Phillips Hue bulbs in lamps and ceiling fixtures to control the lights and just leaving the Light switch on. I have started to put up a few of the Phillips Taps next to the light switches to provide control of the lights. Simple to use. Resonable to set up.
If you decide to go with in wall switches by spares. The home control market seems to be evolving much more rapidly recently and there is no telling how long a technology will be popular and available.