This is so much better. I don't understand why they have to sell the hw whiteboard when everybody could see everything on their tablets and laptops, plus the screen every meeting room already has. Especially since they target remote collaboration.

Is there any app like limnu but without the paid service behind and save to any cloud or local storage?

Agreed. Collusion https://collusionapp.com has free use (not trial), you can also download your work as a PDF/Image if you like without restriction.