The Restaurant Booking particle allows you to manage your online reservations. It is dedicated to restaurants but can be used for many other sectors of activity. This particle uses a platform dedicated to forms, Simple Form, which makes the interface between your site and your mail. Simple Form fits easily into Gantry 5 particles.
The Owl Carousel particle is a simple and elegant particle, based on the open source project of the same name by Bartosz Wojciechowski, that displays featured information in a modern slider. This particle is available in free RocketTheme template Helium. I created a small package for this particle with a small modification at the css level to adapt it to the template Hydrogen.