For the last two or so years, I have been using mtheme (and/or a local variant I called 'm2') as well as the newer (renamed to metropolis) release metropolis for all my RMarkdown-based presentations as you can see from my presentations page.
- the pkg-latex-metropolis package for the LaTeX part (which is also in TeXlive in an older version)
- the pkg-fonts-fira for the underlying (free) font (and this sadly cannot build on launchpad as it needs a download step).
An animated gif containing all pages of the very simple example included here follows:
As an aside, creating the gif is trivial, I used
convert -delay 250 -geometry 480x360 beamerPresentation.pdf beamerPresentation.gif
This is a somewhat static example which may not get updated over time.
The aggregation is provided under the GPL (version 2 or later).