Frontity is a React framework, which is specifically developed for use with WordPress. It looks like a great solution for creating websites with WordPress as a decoupled/headless CMS. Also, Frontity is financially backed by Automattic (creator of WordPress).
I am very interested in Frontity, because it looks like a great alternative to WordPress themes based on PHP: Frontity sites are a lot faster.
A disadvantage to using Frontity (and React) is that the front-end side of WordPress plugins is not working out-of-the-box. This is also the case for Gravity Forms, it doesn’t work.
However, it is possible, as is being proved by the creators of the frontity-contact-form-7 package. Contact Form 7 already works with Frontity. Of course I prefer Gravity Forms above CF7, so I am putting a feature request here, hoping that Gravity Forms will create such a package as well.