Extensive calculator with correct notation

Not only visually pleasing to the eye, but you can tap each invoice on the "spreadsheet" and modify freely. And as you entered the invoice. That makes it a perfect machine for geocachers, who often have to correct invoices, and yet need a good overview.
Many functions in the graphical part, incl. An export to CSV (for Google Spreadsheet or Excel) round off the computer. Very good.
Why only 4 stars? Because the Amazon version lags behind again with the update.
Please update your Apps Developers in the Amazon App Store, too. Amazon Should put a little pressure on devs here. It's annoying.