I bought a Smart-me Plug about a year ago. Here some thoughts:

• Setup was very simple and straight-forward.
• The app looks a bit outdated – definitely no Material design. Especially the graphs could be a lot nicer (interaction, zooming, filtering).
• The temperature sensor worked initially – but after a couple of months showed values with an offset (e.g. 13°C instead of 20°C). I got the unit replaced in the end.
• The power meter is a nice feature – although I don’t know how accurate it is.
• Setting conditions for switching on/off is straight-forward – although it would be nice to be able to create profiles which can be activated/deactivated.
• The app only works through the cloud. Although it’s nice to be able to switch on/off your appliances from abroad, you depend on this service to be on-line. I also don’t know how secure it is. A stand-alone version with limited functionality would be a plus.
• There is a REST API (although I haven’t tested it) – cloud-only.
• The plug is quite expensive – the build quality doesn’t match its price.