TaxJar - TaxJar simplifies sales tax filing for eCommerce sellers.
Fantastical 2 - Fantastical, the Mac calendar app you'll enjoy using. Quickly create new events with natural language input and more.
Octobat - Octobat provides automated tax-compliance and accounting for digital businesses.
Google Calendar - Spend less time managing your day & more time enjoying it
Avalara - Cut tax compliance costs, not corners. Avalara automates tax compliance and can help improve accuracy while reducing costs.
Itsycal - Itsycal for Mac. Itsycal is a tiny menu bar calendar. If you want, it will display your events as a companion to the Mac Calendar app. You can also create and delete (but not edit) events. Download Itsycal for macOS 10.