I too am interested in an automated system taking data from things like smart rings/watches, ideally with home assistant integration. Do you mean like basic note taking? something like Joplin could be used for that. I use it extensively. It has a to do checkbox function, which you could use as a reminder, though it doesn’t pop up. You’d have to look at it. I think for reminders etc. you’d perhaps be looking at calendar software, perhaps next cloud, which also includes notes.

I’ve recently switched my music over to jellyfin, using various tools to get music from my Spotify playlists and curating them with beets. More recently than that, Immich went stable so I’ve got it running now in tandem with photoprism. I’d probably switch all the way from photoprism if Immich could read duplicates from the external library when uploaded by a user from an Android & if you could have some sort of android retention policy, like if a photo is older than 6 months and it exists on the server it can be deleted from the android.