Build your page block by block by choosing them from the gallery or using the block builder feature. Insert them and edit content then.
Define any block you edit in WYSIWYG editor as custom block and save it into your personal blocks gallery. Screenshot is generated automatically. You can update existing blocks and use Placeholder widgets there.
Compose your grid with fullscreen Bootstrap Editor. It provides tools for creating and editing Bootstrap structure blocks such as columns, rows, and containers.
Advanced preview of your Bootstrap breakpoints (target widths for different mobile devices) right in TinyMCE or CKEditor will make you sure the content displays fine for all of your website visitors.