Finding anything FOSS with Spotify integration will be basically impossible. Clock You is a great clock/alarm app in general, of course no Spotify integration though. But you can choose custom music you have downloaded on your device.
Open Konsole and copy-paste the following commands, then hit enter to run them:
git clone https://github.com/tailscale-dev/deck-tailscale.git; cd deck-tailscale
sudo bash tailscale.sh
source /etc/profile.d/tailscale.sh
sudo tailscale up --qr --operator=deck --ssh
This will give you a QR code, that you need to scan with your phone. You will have to log in to Tailscale to add the Steam Deck to your Tailscale network.
Try running sudo tailscale update
If this works, i.e. if you don't get any error messages, run sudo tailscale set --auto-update
If you use Decky Loader, I recommend installing the Tailscale Control plugin, which lets you control Tailscale from the Steam menu. You can also use KTailctl to control it from desktop mode.
Nothing about the program itself is subscription based. All of the normal features of an email client (that you would also find in Thunderbird) are available for free. You only need to pay if you want to use their services like Send later, read receipts or link tracking, because these requires backend servers and actually costs the money.
It doesn't work, because it relies on Piped/Invidious. Both are currently broken, because Google is trying everything to block third party clients/APIs/proxies for YouTube.
Well yeah, I agree. FOSS apps do lack features like logging in (to a Google account), the recommendation algorithm, etc. On the other hand, ReVanced is not exactly easy to install for new users. Both approaches are valid and get the job done (blocking annoying ads). I appreciate the calm and pleasant conversation.
I just don't want any proprietary software on my devices (for many reasons, most importantly privacy and user freedom). I can use a VPN to privately connect to the YouTube backend, but things get much harder when the proprietary spyware is actually on my device.
If you want to use YouTube for that, it seems like ReVanced is your only option. But you can also create an account on a Piped instance, and have your playlists synced. LibreTube is the only app that supports this.
Corporations steal from us all the time, and they don't even let us buy their content, they only sell limited access that can be revoked at any time (see https://lemmy.dbzer0.com/post/9531016 or https://lemmy.dbzer0.com/post/12904663). Under these circumstances, there are no ethical issues with piracy.
Tailscale might be the easiest and best solution for this. It's like Hamachi, but more modern and much better. They even have a guide on how to set it up on the Steam Deck: https://tailscale.com/blog/steam-deck
I think Avalonia is pretty great for C# cross-platform UI stuff. JetBrains Rider is the best C# IDE on Linux.