You can access the entire Template Gallery on any mobile device. You don't need a separate sitebuilding app to browse template designs and install a template on your site.
Here's how you use Template Gallery on a mobile device:
1. Browse the designs in the Template Gallery.
2. Preview how your website will look on desktop and mobile.
3. Read about the unique features of templates on any device.
4. Once you are done choosing a template, click on it and enter the Site Setup Wizard to set up your website.
To read more about Template Gallery, visit this tutorial.