BarredText 1.0.5 for Mac can be downloaded from our website for free. This Mac app was originally created by Rorohiko Ltd. The program is categorized as Productivity Tools.
From the developer:
BarredText allows you to anchor a vertical bar into the margin of selected text (for example, to visually mark edits to a text). Once the bar is anchored, it remains attached and will automatically track changes to the text. It will move, expand or shrink as needed when text is added to or removed from the marked area.
You may want to check out more software for Mac, such as PitStop Extreme, 3dissue or FileOpenInstaller, which might be related to BarredText.