This app is outdated. I will create a new one with a new robust database design and share a tutorial. I am currently in school and will not be creating a new one now. There is a lot more to something like this than just a bit of Firebase. This app that I created a long time ago “Greet” is horribly designed (as in a bad database design).
Something like this requires a custom database with an api to query which bits of data are needed. Despite this, it’s something I’ll get around to when I finish school next year.
All the best.