Downloading InfoPopup 1.5 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. The software lies within Theming Tools, more precisely Multiple Desktops. We recommend checking the downloaded files with any free antivirus.
From the developer:
InfoPopup is a small floating window with a popup menus. Currently, there is only one popup menu, but more will be added in the future. This version includes a popup menu that opens a URL with the appropriate Internet application.
You may want to check out more Mac applications, such as Occurrence Selector, which might be similar to InfoPopup.