So, taking note from Rekall Forensic website.
What is Rekall?
"Rekall is an advanced forensic and incident response framework. While it began life purely as a memory forensic framework, it has now evolved into a complete platform. Rekall implements the most advanced analysis techniques in the field, while still being developed in the open, with a free and open source license. Many of the innovations implemented within Rekall have been published in peer reviewed papers.
Rekall provides an end-to-end solution to incident responders and forensic analysts. From state of the art acquisition tools, to the most advanced open source memory analysis framework. Rekall at a glance."
In short, rekall is just like Volatility, which you can get from here. Now let's get started on how to install Rekall in Ubuntu 20.04