Do you just want keep track of things that you’re working on?
If so, IMO, there are better things to use than a spreadsheet. I’ve used Trello a lot recently, and you certainly can keep track of how much time you’re working on something. It won’t do very well at adding things up into a bill or anything, but something like that might work.
Or are you looking for billing related software?
In general when I’m doing direct client work, I use a single quote for the whole project and only bill time on things outside the scope or on post-support. All this is all negotiated out ahead of time, and any additional hours are just approved in bulk when new work is added… I don’t bother opening up my minute-to-minute work to the client, that’s just asking for trouble IMO. In other words, I don’t use software for this, just old fashioned email :)
