I'm using these, with Home Assistant and an Aquara presence sensor to save power in my two car garage. I'm using them with LED retrofitted, quad T8 fluorescent housings. Still have switch control, but the auto off with the presence sensor will save a lot of power.

I like the fact that these can be installed behind the switches in the junction box to add smart home functionality to existing lights. I don't love that when I upgraded the firmware, I had to take it back out to reset it since it quit working.

If you are installing these, do yourself 2 favors:
1. Install them so that you can get to the reset switch without having to remove anything but the cover plate (rear facing forward with the reset button not covered by the switch).
2. Once installed, before you put everything back in the junction box, upgrade to the latest firmware and do the reset.

I also would LOVE to see Shelly put out something with dimmer functionality like this.

The app works great.

If you are wondering how this works, if you turn on the light with the switch itself, it comes on. If you turn it off with the switch, it goes off. If you turn it on or off with the app or home automation software, it doesn't matter which position the physical switch is in. If you turn the light (or fan) on with the switch, and turn it off with the app, it will turn off, and the switch will not work again until you turn it off and back on, but the app works anytime regardless of switch position.

Also, if you turn a light (or fan) on with the app, to turn it off with the switch you just turn the switch on, then off.

I love that this model shows you the wattage. I was surprised how little wattage my ceiling fan actually uses, even on high.

Also, if you are like me and want to take the cover off to see what's inside, make sure you don't lose the TINY reset button, which can fall out.

These use a mechanical relay, so you will hear a tiny click noise when you turn something on or off. It's not very loud, and I don't think it will really bother anyone - just a callout.

Product works great after I spent a lot of time on trying to pair that thing.. the app is very unfriendly, full of bugs so I had to do factory reset several times by shutting the electricity down, then up and press the button 5 times. After the pairing finally succeeded, the app is just horrible so it has to be connect to some smart device such as Siri/Alexa/apple shortcuts etc.
Overall I rated it 4 because I suffered from the installation only 1 hour and now it works without problems (except some app issues)

I've been converting my shop to be automated using tech gadgets like wifi bulbs, electric plugs, and Alexa. I found out about these things and had to try them out. I wanted to be able to control ceiling fans on wall switches and these little devices were the solution. The install was somewhat difficult - mostly because I'm a novice electrician. Once I figured out the wiring in the box, the devices were easy to set up using the app. Now I turn my fans on/off using voice commands. I will definitely purchase Shelly products for future automation projects.

I love these switches, replaced a few z wave ones with these in my setup for use with an IR sensor and it gives me lots of control over my lighting now since they're signal followers and not just a toggle.