Beta 14 introduces few long-awaited features. Now you can manage multiple calculations in Numi. And if you are on Sierra, all your calculations will be automatically synchronized via iCloud. Autosave time improved as well, so, no more (hopefully) loss of data.
Font size option added. By default font size will be adjusted to match optimal size from readability perspective: for larger window size Numi will use larger font, insets, and result panel size. Still, you can tweak this option in preferences by choosing small, medium or large font explicitly.
This update also brings full Sierra support, with adopted look for Today widget.