A problem that I have is a difficulty in valuing my own time. Whenever a client asks for something that I know only takes a little bit, I haven't always charged because it seems so insignificant, but it adds up. Now that I only have to click a button, I don't feel like I'm going out of the way to bill for the small stuff, and it reflects in my pay :)

super simple time tracking, easy to bill for short assignments

Just time tracking, rate, customers, and description - no bells or whistles