RSS, basically. for software with github releases, there's an RSS feed for release feeds by appending .atom to the releases page, like https://github.com/yt-dlp/yt-dlp/releases.atom
check out nitter.net for twitter RSS, has been going strong through API changes. also since you mentioned Apple stuff, it's not per small update but they publish major stuff on the Newsroom feed which has an RSS feed: https://www.apple.com/newsroom/rss-feed.rss
also you might like https://www.techmeme.com/ as a high-volume aggregator.