Right-click on a tab and choose "Pin Tab" from the context menu. (there is a note about that in the first link in supplemental information below. Please bookmark your app-tabs into a folder so you can restore them all at one time anytime. ---- supplemental information: Make app-tabs work even better by installing the "Multiple Tab Handler" extension so you can close all tabs, any selection, and fast things like close all tabs to the right, or to the left. In fact you can even close only the unselected tabs. Another really nice thing about the extension is the ability to document in various formats selected tabs that you have open title, url, description and other META data however you want, so I have several formats for each of text like in email, for HTML, for wiki. Postings here are very similar to wiki. * https://support.mozilla.com/questions/872310 Another useful extension that you can use with app-tabs and/or "Multiple Tab Handler" is "Add Bookmark Here2" which is also mentioned in the above link.