There are copies of the latest versions of the Focused and Function Calculators available for free by tapping the "Downloads" button at the bottom of the calculator list
The top section contains the list of calculators that you have, but there is a newer version available.
The bottom section contains the list of calculators that you do not have installed.
Tapping the rows will select/un-select calculators to download.
Tapping "Download" will download the selected calculators. They will appear at the top of your calculator list.