usabilty for marine application

[BugQContri]

The app is due to its simplicity ideal for maritime application. However the following changes are needed.

Absolutely needed for usability at night on board (=good night view not blinding the eyes):
Black background with a mid red

• thick line (much thicker than current v0.2.3) for the atmospheric pressure
• all other characters and thinner lines in the same red
• vertical and horizontal lines a bit thicker
• horizontal scale in large chart: hourly units

Additional feature for maritime application (This would be great if a sudden depression approaches at night with limited sky visibility or a tired person on night duty.)

• Notification with audible alarm for changes in atmospheric pressure in a certain time.
• Notification threshold settings: change of x hPa in atmospheric pressure during y h.

I can be contacted for discussion and testing.