Hi Paul,
The 16-day forecast works for me, although I did spot a typo in the settings, it does indeed say ‘3-hour interval’ instead of ‘1 day’. However, this does not affect the working of the 16-forecast.
I have updated the app, I’ll submit it to the store once I have made some V2 screenshots to add to the Readme. The update can be installed right now using the CLI install method.
What exactly have you tried with the 16-day forecast that doesn’t work?