I'm doing more and more freelance work and need a better way of invoicing with time tracking + expenses. One that takes an online payment from a client would be great, but not required.
For time tracking, I've been using mite by quirky German company Yolk: http://mite.yo.lk/
Weird name but the product has a great UX and a no-frills approach with focus on just the essential features including an API. At 5 EUR per user per month it's reasonably priced as well.
For invoicing I use a plain and simple LibreOffice spreadsheet template and email.
I like invoiceninja. No connection, just a happy user.
It's been going a few years, open source, free (paid option for no branding), payment gateways and so far has been reliable. You can also set scheduled recurring invoices, even on the free tier.