Eco app idea: Scan your trash & know how to recycle it

Hi all,

I came over this app Wastify and thought this was a genius idea. But sadly it doesn't seem to have many downloads and the author seems to have left the project since.

I am trying to study if such an idea would work, so I released a post on an environment group on Facebook based in Taiwan (where I am), and received 200 reactions and more than 20 comments within 24 hours. I know it might not be a lot for many of you, but for me this honestly took me by surprise.

So I made a landing page within 5 hours, and put it back out. I said if this gets 1000 emails within 2 weeks, I will start building it. As of today, it is day 1, so we shall see in two weeks.

My landing page is all in Chinese, so here is my TL;DR rough idea for the app:
Stage 1 - use phone camera to scan the recycling icons on the container and show users exactly how and where to deal with it
Stage 2 - build a community for users to exchange info on environmental ideas, events
Stage 3 - expand to cover trash that doesn't have icons on them
Stage 4 - build second-hand marketplace for buying/selling furnitures/appliances

Has anyone here tried something in similar realm? Please grill me.