SIERRA is described as 'When it comes to investigations, be it OSINT, Pentesting, journalism, or data analysis, the devil is in the details—details often buried in cumbersome tools and convoluted notes. SIERRA revolutionizes this process, acting as your all-in-one investigative dashboard' and is an app in the office & productivity category. There are more than 10 alternatives to SIERRA for a variety of platforms, including Windows, Linux, Mac, Web-based and Self-Hosted apps. The best SIERRA alternative is Blackbird OSINT, which is both free and Open Source. Other great apps like SIERRA are SpiderFoot, Maltego, OSINT-tool and PhoneInfoga.