Concrete5 lets you assign permissions for files in sets, but what about files not in a set? (Hint: add them to a set!)
Unit of measure calculator
During the course of creating product catalogues, the need often arises to work out the unit of measure for a product. Surpised that such a thing didn't already exist online, I've made my own!
The first version was quickly pieced together as a proof of concept which was in use for several months. When I revisited the code to expand the options, I decided to completely rewrite it to take advantage of the template rendering of Underscore.js and standardised the form elements with Bootstrap 3.