This was done with Krita, which is a free painting programme.

Based on a detail of a Burano Island photo I took some years ago. I have been wanting to dip my toes into digital painting and downloaded Krita last week.
I find it hard, and the amount of things to learn overwhelming, especially brushes. But it’s meant to be fun, part of my new illustrating hobby. So, keeping it simple: for now I will just focus on getting used to sketching with a tablet pen in the first place, which feels awkward in my hand for now. For the above work, I roughly traced the outlines over the photo, before filling it with colour. I hope to get used to the pen soon, well enough to sketch freehand.
If you interested to download Krita, click here for the link.