We use Google Hangouts free to create a subdomain you can log in with your email account and invite anyone else that has the same subdomain and is very secure. You can share screens and draw stuff, which is essential to conveying ideas to a remote team of engineers.
QuickBooks is not bad, once you get used to the interface. It is nice that it integrates with your bank account and automatically categorizes all the expenses. My accountant is glad that I am using it.
We use GitHub Projects so that we can track everything in the same place. It has the same card based system as Trello and it works for us because it eliminates switching between applications.