https://ntfy.sh/

Easily set up, and easily attached to other things. Simple notifications about whatever is needed, like service health or updates, new posts on public platforms, etc. A simple curl is plenty to send and receive notifications, and it works on Android without requiring FCM (Google infrastructure).

I use mautrix/discord, it can work in both puppeting (sign into your account) mode and relay (bot account with webhooks) mode.

1. A puppeting (personal account) Discord bridge basically requires your own homeserver. You are trusting the homeserver owner / bridge host fully with your Discord account.
2. It is technically against Discord ToS. While I don’t think anyone’s been banned yet, several people have started receiving warnings that they “spammed”, most of them after sending an attachment. These warnings are on your account for 2 years, and could contribute to an account ban.
3. Voice chat is not, and probably will not be supported.
4. Do NOT bridge a “large” server. You are essentially re-hosting the chats, which can be extremely taxing for large and active Discord servers.

I use mine for a single channel in a “medium-size” server (~2k people), a friend group server, DMs, and a few channels that follow a bunch of announcement channels on other servers.

Depends on how it’s implemented. Anyone using a “media proxy” will see their discord bridged media probably fail to load (outside of possible caches) after a day. Anyone who has their bridge configured to reupload discord media to their homeserver should see no change.