This bot is what I was waiting for. I've used SteemWatch but it didn't work well on mobile (Steemit.Chat via Rocket.Chat).
Discord notifications works well, and for me, Busy integration is a great bonus, so I won't just use @ginabot to see my notifications, but for interaction when I feel necessary. It's more comfortable than always rewriting the URL.
I'm glad that it will be open source.