We use Airtable to manage our accounts and their contact information, tax ID, mailing address, etc. We use Wunderlist on the side which acts as a project manager, ensuring that we send all of the necessary communication to each account throughout the duration of our relationship.
I would love to see a feature which allows a checklist to be embedded within the database. In grid view, this would have a single cell which, if clicked on, would show an interactive checklist that pertains to that specific record. This would allow us to eliminate Wunderlist and use Airtable as our CRM and project management tool.