It works perfectly (in a water heater along with a relay).
It only works with the eWeLink app, which is not one of the best and this is also restrictive.

My electrician didn't install it properly on the panel. Other than that, it's fine. Especially when you turn it on, it makes such a noise that even the neighbor can hear it. Pay attention to the connectivity instructions, there is a small detail that can confuse you... I won't tell you what...

It has been installed in the attic along with a power relay in combination with a temperature sensor and custom firmware. It has been functioning without any problems since 2017.
The initial software is somewhat difficult to install, but afterwards it works without any issues. It has been installed in the central heating thermostat in the village. It has been functioning without any problems for two years.
For the money, they are excellent, but you should know what you're doing or call an electrician.

Very good, as long as you know what you're asking for. I wanted it for the water heater at home and it works perfectly. However, be careful, I had to bring an electrician friend to install it correctly, and besides the Sonoff, we also installed a power relay (and an additional switch for bypassing the Sonoff in case it breaks). The application is okay, but if I log in from my phone, it logs out my wife and vice versa, so we have to reconnect again. For its price, it's fine, but if it's for an electrical panel, consider additional costs for an electrician (don't mess with the panel...) and possibly some extra materials.

It works perfectly! I have used it in a variety of applications (even for the Christmas tree) without any problem. The function of scheduling provided by the application is also important. In fact, you receive a message on your mobile every time the device changes state.

I have connected it to a power relay for the water heater. It does its job perfectly. I have connected it to a Cosmote router. And the application is very good. You can program it to turn on and off at any desired time.

I got it to make my water heater smart. EXCELLENT! On YouTube, you will find videos on how to connect it with a power relay. In case you don't have WiFi at any moment, it has a button on it and can be activated manually.

I have been using Sonoff without any problems for 4 years. They are reliable and stable. At first, I struggled excessively to create an account for the application (to the point of throwing them in the trash), but two months ago when I created 2 accounts for friends, there was no issue. Excellent value for money.

Personally, for its price, it has made me have a white face. The application is user-friendly but it requires some exploration to understand it

Excellent! Affordable, connected instantly to the eWeLink application and was recognized by Google Home Mini as well.

The product is amazing for its price, I installed it in a water heater and if the application wasn't so bad, I would give it 5 stars. Initially, it took me over 2 hours to connect it to the application and every 2 days it kicks me out and I have to enter the code again. For me, it's not a problem but for my wife it is, as she can't use it.

The worst thing you can find in a wifi switch .. for the same money you can get several companies with better menus and play with tuya and not only with ewelink .. one of the ones I have ended up with is this https://www.skroutz.gr/s/21598779/Woox-R4967.html

Initially, they couldn't connect to wifi with iPhone on iOS 14, but eventually they connected with iPad (again on iOS 14).
Once they connected and a software upgrade was done, they work flawlessly (and also on homebridge).

Tremendous value for their price and truly, if they fit your hands even a little, they are an exceptional case.

Very good product, easy to set up. Connected very easily to WiFi and works with Google Home/Assistant. It also has various programs that can automatically turn on or off, such as a timer, if it's day or night, and various other settings. It also has a setting to return to the same state it was in before a power outage.
The connection is very easy. You "cut" the phase-neutral for the input and connect the phase-neutral to the output. It has detailed diagrams in the manual. Unfortunately, grounding does not pass through the component.

I have this particular product for about 6 months and it works perfectly. It is connected to Google Mini and Google Home. It has an immediate response to voice commands. Of course, there is also the company's application with which it can be programmed to activate and deactivate according to needs.

First automation I got for use with WiFi and connection to garden lights, used for almost 4 months.
Very easy installation with basic knowledge of electricity, although installation by a professional electrician is always recommended. The connection is extremely simple and easy, the free application being Chinese is in English, it doesn't have anything special apart from the ability to create programming scenarios, timer shutdown, etc. and of course control, although I suppose it doesn't need anything more sophisticated.
Simple to install and use, good WiFi network reception despite being installed outdoors, I had no problem operating it and of course it also has a small button for manual operation.
Overall, it is a very simple, extremely affordable, and so far reliable automation.

Very good and useful. It can be used both for household and professional purposes. It connects easily to wifi and the application has a very nice and user-friendly interface.

I have it to open and close the water heater. It has a timer and even a repeat function. You can tell it when to open and when to close, and on which days.

It has been in operation for 3 days. If anything changes, I will update!

Very good, connected immediately!!
You set it up through the application, command ON and OFF whenever you want!
I connected the water heater in combination with a relay with 2 normally open contacts (for the phase-neutral of the water heater).
Basically, because the SONOFF can't handle many amps, you connect the output to contacts A1-A2 of the relay and give the command to close the contacts so that the 20A of the water heater can pass through the relay (which can handle 25A).

Easy to connect, it has its own application, compatible with Google Assistant. I have installed 3 in some light fixtures, replacing their regular switch with this one. Everything works without any problem. Through the application, you can set automations, which is great! I have had it for over a month and I am very satisfied

The worst thing I have ever bought. I never managed to make it work. Maybe it does work in the end, but the problem was that I could NEVER create an account in the application. After I received the verification code, I tried to create the account. It always told me to try again or register. So I don't know if these things are good or not. I will probably use something reputable to take care of my health because if it's so bad from the beginning, I can't imagine what will happen later.

Very good! It has a good application that works with the mobile phone and can be connected to Google Home or Alexa. For its price, it is amazing! I have had it for about a month and it has not presented the slightest problem

Perfect. The installation took me 10 years of my life until I figured out what was going on. So here's what you're going to do. You will connect it to the power and download the ewelink application. You will create an account and click on quick pairing. When it shows your Wifi, you will click on the switch to turn it on, press it for 5 seconds to make it beep, and then press the pairing button. (Android)

I used it in a light fixture that I have in a corner of the house that would be a little difficult to access in order to turn it on and off. I'm glad I made this choice. Now I can lie in bed and turn it off from there.

Extremely reliable product, I have bought more than two. I use one on a bright signboard and another on the garage door. The mobile app application is very good.