Freelance Invoicing Software

I was just curious as to what other people here use to invoice their clients as a Freelancer. Do you use stand alone software like Quickbooks? or do you use online invoicing software (There's quite a few of those like Freshbooks, etc.)? Do you just create your own invoices using Word or Notepad?

I'm just curious as to what you use. Thanks for the input!

I'm a pretty big fan of quickbooks but it doesn't have anything built in for time tracking. I'm considering a switch to the likes of Harvest simply for the added benefit of time tracking that I can set from anywhere.

Lately I've just written custom invoices in notepad and evolved them as the relationship progressed and easier ways of tracking certain details have been needed.
Now and then I get something good the first time.