$0 budget launch?

Hey Hunters! We just launched Aesty: Personal AI Stylist on the App Store and will be launching here on PH next week. In just 2 days, we already have 415 users and 55 active subscriptions/trials without any marketing budget. To achieve that, I used my social media (2.5k subscribers), collaborated with several fellow influencers on Instagram, LinkedIn and X, and shared launch news through the waitlist we collected with our website. We believed TikTok would help us a lot; however, we did not have anyone from there. I wonder what other options for <$500 budget app marketing exist that I might be missing? Thank you!