Yup! That's the one. The entire Alfred application is just 6.4MB uncompressed (the previous version was 9.4MB, so they've made it even smaller!) And it does a lot more than replace Spotlight searches, it supports plugins for various workflows that you can design with a drag & drop component UI layout, there's a calculator and a music controller (iTunes, but with plugins it can control Spotify), text snippet support across the OS, and all in just 22MB of RAM (on my machine). Runs on macOS.