I have tried this App out after coming across a link yesterday , and initially it said it didn't work with my Surface 3 as the screen wasn't big enough but maximizing the App seemed to fix that ( maybe it was a restart that fixed it?) but it is working fine now in Portrait and Landscape Modes even without being Fullscreen...so far I like it, pretty intuitive after the quick Tut. and there are more Pointers in the Nebo folder too, showing you how to do different edits etc.

It is currently free (usually $8.99) in the Windows App Store. ( sorry can't link it)

This is Nebo's Website though..... get it while you can...

MyScript Nebo

.works for iOS pens too.... but I can't test that...

KB