I use <a href="https://www.getharvest.com/" rel="nofollow">https://www.getharvest.com/</a>. It lets you set up multiple clients, projects and team members, track time and expenses for various project tasks and send out invoices. For invoices, you can track what's been paid and it will send out automatic late reminders. It also has native apps so you can start project timers with a few key presses. There's a free tier that will last you until you get a few clients and the paid tier is cheap.<p>I originally tracked the above manually using spreadsheets but it's so much nicer having a simple interface to keep track of everything for a modest cost.
I've been freelancing for over 2 years now and I use Freshbooks (<a href="http://www.freshbooks.com/" rel="nofollow">http://www.freshbooks.com/</a>) for all my time tracking / invoicing. It also can accept payments via Stripe, as well as connect to my business credit card to automatically pull in expenses, so most of my accounting stuff gets very easy to handle -- I barely log in to it for any management, I just use ChronoMate (<a href="http://chronomateapp.com/" rel="nofollow">http://chronomateapp.com/</a>) to track my time, and it auto-generates weekly invoices to send to my clients. Couldn't recommend it enough!
To track my time I use an app called Hours Tracker Pro on my iPad (it has a Piggy bank icon) and it allows me to set a rate per client/deal and track time across multiple projects/clients. I also had my contractors use the tool and send me the excel file export from it as you can email the time report to anyone. This let me get their time, take the excel files and create my invoices in my accounting application. It did take an extra step and could have been better, but it wasn't a huge ordeal.<p>Then for invoicing and getting paid, I used Wave Accounting (but honestly was moving away from it). At least for now, I use Quickbooks for everything Wave used to do for me. Wave has come out with some new features to solve some of the issues I had and to make time tracking etc easier.
I tried so many different tools, mostly trying to avoid paying for a service, but honestly, there's nothing as good and as simple as getharvest.com. Simple time tracking, simple invoice generation and my clients can pay via a credit card (Stripe integration) right away. It's worth it.