In one of my side projects, I built the core experience as a progressive web app (PWA), then wrapped it using Capacitor to publish it on both the Play Store and App Store. It was a simple app, so this approach worked great.
If your app is mostly content-driven or doesn’t require deep native features, this is probably the fastest and most budget-friendly way to go live on both platforms. Just be aware that performance and native feel might not match that of Flutter or full native apps.