Started freelancing last month and this service has been invaluable

I freelance and find these types of billing/time management applications to provide a service that is invaluable to me. I can more accurately bill clients and easily keep track of the projects I'm working on because they tend to have things like built-in time trackers and integration with popular apps that perform other functions (e.g. project management) that excel doesn't. There is no way that I can do this without a lot more effort with a simple office suite. Alternatively, if I did use something like excel to keep track of these things for a month or two, I've now got to slowly migrate to some other alternative or find a way to input that kind of data into my new choice of app, and that's time wasted that didn't need to be. If you know you're going to do this, you may as well start with what you're going to use. I've switched apps mid-project before, and it was a huge pain to the point that the next time I switched to another app, I was stuck using both the old and the new until projects were finished, just because of the migration hassle. (For the record, the first one was a billing/invoicing one, second was my business to-do.)

On the flip side, I know people that keep track of these things in spreadsheets, they've done this for years, and that's their choice because they like it that way. I can't stand it. Whatever works for you.