When you select text with the mouse or keyboard, Atlantis can automatically highlight other instances of the selected text in the document window:
In addition, the total number of found instances of the selected text is reported through the status bar of Atlantis:
If you click the instance count hyperlink in the status bar:
all the highlighted instances would be selected as a proper multiple selection:
After this, you could perform various actions on the selected items. You could apply a different font formatting, delete the selection, bookmark each selected item or convert it into a clickable hyperlink, etc etc etc. You could also overtype the selected instances with new text. In this way, you could quickly replace all instances of "Alice" with "Jane" without using the Find / Replace tool.
Note that Atlantis highlights instances of a manually selected text only. The selection should also contain entire words not word fragments, and the corresponding option - Highlight instances of the selected text - should be enabled on the "Edit" tab of the "Tools | Options..." dialog.
To configure the feature, click the [...] link in the status bar:
This would display a menu with the following options: