Audiomodern Filterstep

Filterstep is a free multi-mode filter plugin with a built-in step sequencer. It is available in VST, AU, and AAX formats for Windows and macOS, as well as a standalone desktop version and a portable iOS app. The plugin is perfect for creating complex rhythmic filtering effects and adding movement to static sounds like pads and drones. The step sequencer syncs with your host’s tempo and lets you adjust quantization and step length.

It also includes a randomizer for generating new patterns with one click. You can store the generated sequences in one of sixteen preset slots for easy access during live performances. Filterstep works great as a plugin, but I highly recommend checking out the iOS app. It is a great tool for developing musical ideas on a portable device.