tre3rty 2 1.1 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The actual developer of this software for Mac is seyDesign. The application lies within Developer Tools, more precisely Webmaster Tools.
From the developer:
tre3rty 2 is a delightful, responsive RapidWeaver theme, full of powerful features, finesse and a designers touch.
tre3rty 2 utilizes such open-source technologies as jQuery, Twitter Bootstrap, Font Awesome, rFrame, SS3, SmartNav, SmartLayout, Social Links and ExtraContent. Built on a solid and proven framework, tre3rty 2 is sure to deliver solid performance and exceed expectations.
You may want to check out more Mac applications, such as AcidSearch Installer, Browsealoud or RAGE WebDesign, which might be related to tre3rty 2.