* When RSS was a thing but in my country a lot of news/content websites hadn't adopted yet, I wrote a service to quickly define scrapers that turn those sites into RSS feeds.
* In one of my former workplaces I wrote (alongside another person) a gamified shared playlist app that allowed everyone to participate in being a DJ for our company hackathon (people getting more upvotes getting more playtime, songs getting many downvoted being skipped in the middle, etc). That was a lot of fun and surprisingly a very emotionally engaging experience for everyone.