Downloads
Windows and Google Play.
The same calculators and invoices, on a laptop or a phone in the van. Nothing extra to buy.
Windows
Open this site in Edge or Chrome. Use the browser menu and choose Install app. It sits on the desktop and taskbar like any other Windows program.
Google Play
On Android, open the site in Chrome and add it to the home screen. The Play listing uses the same membership once the store build is live.