macOS application for making photo collages with arbitrary rectangular grid and sizes.
macOS 10.10 or later
Click with right mouse button inside any frame to see pop-up menu that allows you to split current frame or to upload new picture. All you need to change size and proportions of the frames is just a move of a mouse — drag frame border with left mouse button. You can also change application window size for that purpose.
Export to Facebook may fail if your account doesn't linked to your computer in macOS settings.