Currently the SpeedScriber app is only available for macOS.
However the SpeedScriber panel for Adobe Premiere Pro is cross-platform and available for macOS and Windows. By using a single SpeedScriber account, you could have one macOS system importing files (and editing if desired) and then multiple systems running Premiere Pro on Windows which can access that transcript data and add it to clips.
The administrator portal for seeing usage, buying minutes and changing default billing information is web-based at app.speedscriber.com