Create Custom Page Templates

Is there a way to create a custom page template for the wordapp themes?

At the moment when I create a menu item which links to a post category page, the page in the app only displays a list of the posts, not each post one after the other with featured image, title and description.

I would need to edit the theme page template to achieve this. Is this possible? I have not been able to find anywhere to edit the theme files as yet.

Thanks in advance, and for a great plugin!

https://wordpress.org/plugins/wordapp-mobile-app/