This is my daughter's first real project. She is a 3rd grader. Of course, it was a guided project but see learned a lot in the end. :-)
We have a fish tank with 10+ fish and need to feed them twice a day. It's very easy to forget as they don't ask for food like our dog. So we wanted to automate the process and forget about feeding them altogether.
There are many products in less than $20 on Amazon but we decided to do it ourselves and give my daughter some coding exposure. We have used AWS Cloud to update IoT shadow which ESP module listen to. You can use any MQTT broker to establish the communication. We also used ESP deep sleep mode to reduce power consumption. As a downside, it does not run on exact minutes you want but within a window of 60 minutes. It was not critical drawback for us.
Watch the demo on YouTube!