The app is available on Windows and iOS and you can share your projects between different devices and send them to other users to view. The only nuance is that the "publish to web" (a feature that allows you to upload a project to a website as an interactive experience) option is only available on Windows devices.
Speaking of the technical side, Mental Canvas works with any pen and multi-touch tablet running Windows 10. A drawing tablet without a screen might be a challenge to set up for Mental Canvas though the developers say you can give it a try. So far, you can import images into your Mental Canvas scenes and export them as MP4 videos. Importing videos or 3D files and exporting your creations as 3D models are not yet available though these features might be added in the future.