DuplicateTab 1.2 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The software relates to Internet & Network Tools. The actual developer of this free Mac application is SpanLabs.
From the developer:
DuplicateTab is a browser extension that provides two convenient ways to duplicate a tab in Safari. You can either show in right-click dropdown or activate a new toolbar item when duplicate. Both options can be enabled and respectively, disabled with ease.
You may want to check out more software for Mac, such as NetZero, PointerServer or KIDOZ, which might be similar to DuplicateTab.