Hi! I am Romana Diana Castillo and I do create book covers! The app that I use in creating book covers is Canva and I had been using it for 3 years now.

Here's an introduction to Canva:

Canva is a free graphic design platform that allows you to easily create invitations, business cards, flyers, lesson plans, Zoom backgrounds, and more using professionally designed templates. You can even upload your own photos and add them to Canva's templates using a drag and drop interface.