Thank you for your answer! Why do I need to know who is my audience? => You mean Android or IOS?
I think it can be better to begin by an "everyone" approach, I will have a look on the Toggle Device Mode, thank your for the info!
I saw it, it's very great!!
You also have https://ecodrain.com/en/ a tube heater who recycle the already heated water!! Have a look on the video: brilliant!
There are also a lot of different projects about watering plants, gardens, or agriculture.
But it's still kind of hard to search in search engines, and have great content...