I lost my iPod classic some years ago 😢 I used to use the same rockbox theme as you, I miss it so much.

My most useful is probably ntfy & my matrix client, Element. I self-host ntfy & a matrix dendrite server with some bridges. I am able to receive notifications from all of my chats without Google services installed, as well as notifications from Tusky thanks to Element and Tusky’s support for UnifiedPush.