We have used InVision in the early stages. I personally think that it is not a great use of your time, because you end up spending a lot of time creating something that is not real. It’s great for presentation purposes if what you want is to sell a website or app. If I were to go back, I would start implementing the website right away and iterate on it rather than spending so much time on wireframing something that isn’t real.
We use Google Drive a lot. It helps keeping all different types of documents (spreadsheets, presentations, word docs) in one place, and we recently switched over to keeping our digital design assets stored here too.
We use Mixmax for email management. As we scaled and my schedule changed to be more in a managing role, I ended up spending large parts of my day in meetings. Mixmax makes scheduling meetings a lot easier.
I am pretty happy with Basecamp. We just brought on a product manager who will help us get better at utilizing all the tools. Often with project management software, half the battle is becoming well versed with the full range of tools it offers.