Default homepage and several subpages in Melvin template demo were created using SP Page Builder Pro 3.x component. 

Within this page, you are availed with easy customization functionalities with SP Page Builder 3. Page layouts are created with pre-built SP Page Builder addon and row/column options. Every addon holds information for particular sections in the layout. You need to customize these addons with your desire contents like images, texts, and designs. 

Customize everything in the frontend

For frontend editor you just have to click the frontend editor on top of SP Page Builder and login to your template. Now click edit page. With this frontend editor will be activated. You can enjoy amazing drag and drop also row option editing functionalities with the editor.