This plugin will made your header or menu fixed and sticky.

Simple Floating Menu add a simple floating button with various layouts and settings.

If you are using a sticky, fixed menu or header in your WP theme, this plugin is the best to deal with them overlapping anchored content.

Sticky Menu allow you to choose any element like header, menus, sidebar etc on your page that you want to sticky at top when page scroll.

Sticky Popup is a simple and easy wordpress plugin used to add popup on fixed position like bottom, left or right side with CSS3 effects.