Dear Madam or Sir,
I am an experienced Python programmer and embedded designer. Thus I have already developed programs on the desktop PC which interact with sensors like your smart plugs and I have developed the software for the sensors itself. Though, I used different gateways, I have not worked with Smartenit Gateways. But from looking at the API it is similar to others.
I would develop the program in Python with the QT for the GUI. Therefore, the program will run on every major operating system, including Windows, Mac, Linux. Moreover, I would strictly separate the function from the GUI which allows you to run the program without the GUI. When the program runs in the background all the data would be stored in a database or CSV file.
The program would list all the fixtures that are currently in the network or have been recorded in the past. Currently active devices can be switched on/off and charts can be displayed for every fixture which show power usage/ mean power usage and cumulative consumption. An function to export it to a jpg will be provided.
I am looking forward to chat with you, though you have already stated you requirements very clearly and there is not much else to discuss. Bear in mind that my bid is the lowest but the quality of my wotk is top notch.
Best regards