Kirnu Interactive is a Finnish music software developer founded by Arto Vaarala, known for MIDI tools and synthesizers. The company's profile rose with the release of the original Kirnu MIDI Arpeggiator in 2011, followed by Cream, a VST/AU/AAX MIDI performer plugin offering four independent tracks, twelve patterns per track, chord memory, and a pattern sequencer for chaining motifs together. Cream is widely used by producers as a creative arpeggiator and step sequencer for generating bass lines, leads, and rhythmic parts inside a DAW.

Alongside the desktop plugin, Kirnu Interactive ported Cream to iPad as Cream Mobile, bringing its arpeggiation engine to iOS-based production setups. The company later expanded beyond MIDI tools with ButterSynth, a hybrid six-oscillator synthesizer that combines wavetable, FM, sample, and granular synthesis in an AUv3 and standalone app for iPad, iPhone, and macOS.

Kirnu Interactive operates as a small, independent developer, with Vaarala handling design and development. The company occupies a niche in the MIDI effects and mobile synth space, with Cream in particular earning a reputation among electronic and dance producers as a flexible alternative to a DAW's built-in arpeggiator.

Kirnu has 2 products cataloged on Equipboard, including Sequencer Plugins and MIDI Arp Plugins.