Procreate.

 I recently attended a great 2 day workshop with artist Richard Impey on the use of the Procreate App on my iPad. We obviously only touched the surface of the capabilities of this App even though the course was 10 hours over 2 days (with time for lunch!) This above is all I managed to create, as I used my old large format iPad on the first day, but found that as it was so old, that it didn't have the functions that Richard was demonstrating. On the second day I used my mini iPad with a more recent version of Procreate and created an imaginary scene of mountains, river and rocks. What a steep learning curve Procreate is, as it's really quite different to Photoshop which I use routinely. I hope to eventually own a large format up to date iPad and to really get to grips with this excellent program!