One of the reasons why keeping a journal is a worthwhile investment is that you can improve your writing skills over time. The best way to get good at something is to do it more, and with this in mind, Diarly has some tools built-in into it so that you can track how much you write on different journals.
While writing, you can see how much of the target you have already reached with the percentage counter in the bottom right corner of the editor.
Statistics are available for your daily journal entries. As notes are something you keep and modify over time, they don't count into the writing stats.