just to let you know there seems to be a clash between WP Masonry and Advanced Custom Fields Pro (version 5 at least).
If I activate WP Masonry when ACF is active, the WP Masonry menu does not appear. If I deactivate ACF Pro, then the Masonry menu appears.
Unfortunately ACF Pro is central to my WordPress development process, so I’ve had to go with another Masonry solution for now. But WP Masonry looks pretty good – I’ll definitely consider using it if the clash with ACF Pro is rectified.