Gridzzly

Very useful One Pager by Czech developer Rostislav Blaha that provides a customizable grid to print and then design with. The ad in the corner feels a tad chunky but I can appreciate it.

This website has unfortunately been redesigned or gone offline, so I have removed the direct link to it. The screenshot below hopefully preserved enough of the design but if you are really keen to inspect further, try this Archive.org link. FYI: the site was first featured on 05 May 2014.