Kompyte allows you to track what your competitors are doing and learn from them.
Our product teams uses Amplitude. They are happy with it. They have a really large free tier.
Google Analytics is really complete--you can learn a lot by using it. It is not very easy to tailor to your needs. You will never use many of the functions that it offers.
Pipedrive's cost/quality is very good. It might be lacking some features but it is really simple and easy to use, has a low learning curve for new people, is affordable and has a pretty good API.
We feel that Intercom is a little too simple for our needs, therefore we are about to switch. It has some limitations on the communication part. Auto messages, the automated emails sent to your customers triggered by some event, won’t send to any given user more than once.
FindThatLead is a great tool for outbound lead generation--it guesses the emails for you.
We use Appear.in for conferences. You just click a link and it allows you to start a conference. It is very simple and totally free. It has everything for demos, and screen sharing.