Free inbuilt iphone apps help measure altitude and azimuth movements
When observing the night sky on a shoestring, free native apps for iPhone can sure help out!
In this video, I remind viewers to use Compass (for azimuth bearings) and Measure (for altitude angles).
Using a phone at night requires a dim screen brightness and red colourisation, and Inshow how the iPhone offers this for free natively in Accessibility menu settings.