I love how easy it is to use, especially with projects and hashtags. I love seeing all my time color coded, it keeps me motivated to work harder to see my pie charts get bigger.
I dislike that there isn't a way to mark time for items that are not work projects. I'd have to get a separate account to be able to track those items. I'd prefer if it was done similar to unbillable hours, maybe marking a tilde (~) or something similar in order to designate projects (like chores, reading, cooking, exercise, etc.) that I want to keep track of, within the same account but with separate stats.
Since they're mostly reaching out to businesses, I understand why they wouldn't want to invest on something for separating your personal hours versus work hours, but I think a lot of people would love to see how they're spending (or wasting!) their time using this same format, without the added price of an another account, but more so, without the added work of logging in and out to switch between work and home time tracking. There is a huge market of people who want to track their time at home so they can be more productive, and the market is just waiting for something as beautiful and easy as Freckle.
USE FRECKLE! If I had the money, I'd get my husband and best friends on Freckle so we can all see where our time is going. When I get some more money, I'll definitely be buying my husband an account so he can track how much time he's spending drawing, which will help him figure out the rates he wants to charge as well.
Mainly, knowing how much I work on various projects. I've been able to charge a by-hour rate instead of a by-project rate, which has increased my revenue.