while not exactly $500/month, my side project Whenish (https://apps.apple.com/us/app/whenish/id6745035749) makes me some beer money.

I made Whenish cause i was frustrated with apps taking you outside of group chats to schedule events and find out dates when people are available. Whenish is an iMessage extension app and it works pretty nicely so far.

recently got my first user feedback email which was really exciting!

hope to figure out how marketing works to get some more users and hopefully double downloads + sales next year.