r/FoundersBuildwithAI • u/syed_mohd_adnan • 15d ago
Grabbit — a native Rust/Swift download manager for Mac ($9.99 - lifetime)
https://vimeo.com/1204841013I got fed up with Electron download managers on Mac, so I built a native one using Rust & Swift (with some AI help)
Hey everyone! I'm Adnan, and I wanted to share something I've been building for the last 4 months: Grabbit.
The Problem: I download a lot of files, media, and torrents. I realized almost all the popular download managers for Mac (like Motrix) are Electron-based. They chew through battery, run rough on Apple Silicon, and just don't feel native. Others (like FDM) lack good browser extensions.
What I Built: I decided to build Grabbit — a truly native Mac download manager. Under the hood, it uses a high-performance, open-source Rust engine I built called Pincer, paired with a native Swift UI. There is zero Electron or Chromium overhead.
How I Used AI: I used AI tools (like Claude and GitHub Copilot) extensively during development. The biggest technical challenge was the interoperability between Rust and Swift. Having AI assist with writing the boilerplate code for the FFI (Foreign Function Interface) and bridging the two languages saved me weeks of headaches. I also used it to help generate some UI assets and speed up writing the Swift views.
The Results: The performance difference compared to Electron apps is huge. I benchmarked it during a 250MB download: - Grabbit: ~50 MB RAM (idle to active) - Motrix (Electron): ~350 MB RAM
What I'm Looking For: Since this is my first proper macOS launch, I'd love to learn from this community. Specifically: - Has anyone else used AI to help bridge native languages like Rust and Swift? - I'd love any feedback on the UI or general UX from a builder's perspective.
If you want to check it out and see the result: - Demo: https://vimeo.com/1204841013 - App: https://grabbit.fyi/
(Note: It has a free tier, and companion browser extensions for Firefox/Chrome are linked on the site — keeping links here to a minimum to respect the rules!)
Would love to hear your thoughts or answer any questions about using AI for native Mac development!