Don't be fooled by the app's icon, Jammy doesn't really have anything to do with tools or a tool box. What it does have to do with is making easy to use databases directly on your iPhone for you to keep track of things. You can manipulate and create every aspect of the database to your own desire.
You don't really need to know anything about databases either, which is pretty handy for those of you who don't (see also: most of you?). You just load up the app and go through each of the sections that you want to alter. There's the different individual items that you're going to be classifying, the different characteristics that they fall into, and the various options that you can have for each of those characteristics.
It's honestly hard to try and describe how this app works, but it makes a database that is really handy. The issue is that you can't export it at all, making it a lot less useful. If you could port your work out onto your computer, then you'd have a lot more functioning of a database. Especially if it was something you could send back to your iPhone when it's done.
Jammy's limitation of only one database at a time, plus its inability to export make it kind of difficult to use for big projects. Seeing that it's the first database app of it's kind, it's a step in the right direction. It's just not quite at its full potential yet.