Idea Summary
Items in Navigation Bar are buttons that have a Badge Value option.  Buttons added to a form or report have almost the exact same template as Button (Plug-in) minus the badge value.

Use Case
Buttons with a count of records for a report it may open or additional dynamic button information that may help a user.

Preferred Solution (Optional)
Add <span class="t-Button-badge">#BADGE_VALUE#</span> to the Button [Plug-in] template and an option in the Appearance section of the Button property editor to allow setting the value by Item or Expression similar to how computations set values.