Useless just like the kids below say,
Don't waste your money on this thing because it's just a thing.

At first, I was excited about the product.
It seems to have very good build quality, and there aren't many that are both smart and have independent switches for each socket... the app, although it has some lag, does its job...
However, for the past few days, it has been showing a very strange bug:
when all 4 sockets are turned on... regardless of whether you have something connected to them... after a while, it crashes and shuts down... and the only way to open it again is to unplug it for about 5 minutes and then plug it back in...
I have tried everything... I activated factory mode,
connected via telnet and made various changes... still the same... unfortunately, I have lost the receipt to return it...
such a shame because it was nice.

It works perfectly for as long as it stays connected to the WiFi you have. After a power outage or at random intervals, it loses connection with the app (even if you can see it on the WiFi devices in your network) and the only way to restore it is by doing a factory reset. It has the classic issue that many similar devices have, that it only works on the 2.4 frequency.

Although the product appears to be of high quality in terms of appearance, its difficult and completely lacking in functionality D-Link control program makes it useless.
I also tried to connect the device to dozens of other smart device control programs in order to add at least the ability to automatically turn off the device's sockets with a timer, but in vain.
Having purchased other smart sockets and devices, I can confidently say that this is the worst one by far.
It's a shame for the money I spent.

I bought it for aquarium management when I'm away on vacation. It's a black fate if you're away and the power is cut. It loses all settings and also the connection to the wifi, which can only be restored by resetting the power strip. Stay away from dlink!!!! Maybe it will work properly if you connect it to a UPS. Similarly, I found another one from tp link that restores itself no matter what happens.

-Update 22/04/2020
The product was returned to the service and I was informed that it was replaced. I am waiting and will return as soon as I receive it.

-Update 11/08/2020
If there was a minus, I would give it. Unfortunately, after the service, the power strip has the same behavior. I came back from vacation and the power strip had lost its settings for 10 days. It destroyed my aquarium. It is the most useless product I have ever bought. D-Link's service is terrible. It will be returned to the store where I bought it. It's a shame because it looks high-quality externally.

-Update 14/01/2021
With Covid, etc., I couldn't return it to the store after all, so I decided to give it another chance.
After the latest application update, the situation got worse. Also, after every power outage, it continues to lose its settings and never recovers. I have to reset it and start over. The only solution is to have it on a UPS, which again costs you money to get it and you have to work with workarounds.

-Update 26/01/2021
It has been returned to MediaMarkt. I am waiting for a replacement or a refund.

-Update 01/06/2021
They sent me a faulty power strip again from Dlink's service. It still loses wifi when there is an outage. And MediaMarkt won't refund me.

In short, I'm keeping it to use it as a regular power strip for 80 euros.