You can use Textile + Graphic Novelist markup in the note entry field.
Also, you can specify tags by prefixing the tag names with an 'at' sign (@), and the category by the pound sign(#). For example:
My app should be really cool! #MyApp @features @ideas
That note will be categorized under 'MyApp' and tagged with 'features' and 'ideas'. It doesn't matter where you put the categorical meta data, Maelstrom will find it.