Rated 4 out of 5 stars

For some reason, pinned tabs seem to reload instantly after "unloading" them.

This review is for a previous version of the add-on (1.5). 

browser.sessionstore.restore_pinned_tabs_on_demand

"browser.sessionstore.restore_pinned_tabs_on_demand" is your friend in about:config.

Please see detailed instructions on https://support.mozilla.org/en-US/questions/940656#answer-377837

By the way, I'm planning to add a checkbox in options for this pref.

Works just as expected Rated 5 out of 5 stars

When starting firefox again with all the tabs from the last session, the non-active tabs are made transparent to indicate that they didn't load yet.

This review is for a previous version of the add-on (1.5).