ClientSynq
I recommend systems for a living. This one I built.
ClientSynq pulls straight from QuickBooks Online and puts the answers where people can reach them. Customers see their invoices and billing. Your team sees the numbers their roles call for. Nobody waits on an email.

Why it exists
A person should never be the integration
It started with a simple problem. Customers calling to ask what they owe, when the answer was already sitting in the books with no way to reach them. So I built a portal where customers log in and see their invoice history and billing, live from the ledger.
The same wall exists inside a business. Owners and department heads need numbers, but nobody wants to hand out logins to the whole accounting file. So reports get exported and emailed, and a person becomes the integration. ClientSynq removes that job. Information flows to each person, shaped to their role, current because it comes from the ledger and not from an export somebody remembered to run.
How it's used
Everyone sees their numbers, nobody waits on an email
Each user gets a role and sees what that role needs. A customer sees their invoices. A budget owner sees their department. The controller sees everything. And the feature list keeps growing. File exchange with audit logging, reclassification tools, data visualizations, with more landing all the time.
It's built for small and mid-sized businesses. My own engagements run on it, it's included in every one, and outside an engagement plans start at $14.99 a month.