verassol

1. Install UBlock Origin
2. Click the extension’s icon
3. Click the gears icon for settings
4. Open the “My filters” tab
5. Add a line with ||accounts.google.com/gsi/iframe/select?*

Steps 2 and 3 can be replaced by going to about:addons, finding UBlock Origin, clicking the ... button and selecting “Preferences”.

Perhaps Firefly? It is meant for personal finances but considerably complex still. I am not sure if it does invoicing though.

Edit: This should give you a more precise idea of how fitting it might be: https://docs.firefly-iii.org/explanation/more-information/what-its-not/#business-finances-small-business-accounting-payroll-management