Depending on which "Aeon" you are looking for, here are the official ways to download or access them for free:

: It is available as a free download on the iOS App Store , also supporting the read-only feature. 2. Aeon (Music Visualizer)

: You can download a fully functional 14-day free trial for macOS or Windows. No credit card is required to start.

: All essays, videos, and guides are free to read online .

: A limited free version is available for download, which includes real-time audio response and various visual combinations. 3. Aeon (Digital Magazine)

If you are looking for the audio visualizer by SoundSpectrum: