Tabbed Multipage Ajaxified Forms
You can look at Multipage jumplist module which provides a block that allows you to access all multipages.

To apply the ajaxified multipage fieldgroups, use: Field Group Ajaxified Multipage module which allows you to enable AJAX for multipage groups
It also provides developers with special variables attached to form array regarding page status to allow them further customize the form (e.g. form_alter) depending on active page (in this case saving your pages).