App suggestion for low-friction way to log regular text entries?

I would like to keep a log of what I have been doing every hour during my work day. I would like something (say, an app or menu-bar utility) that will pop-up every hour and ask me what I have been doing, allowing me to enter a few lines of text. The fact that it would automatically pop up, and that it only expects me to fill in one text field would mean that it is a very low-friction way of entering information. It would, of course, then have some way to let me view what has been logged post-facto. Can you recommend anything that will let me do this?