I suspect this is cedar rust on my apples. Middle Tennessee. Any ideas? For whatever reason, cedar rust is not listed on this app.

J Hanner Looks like Algal Leaf Spot, pls review it. However, your assumption is quite right that the symptoms are very transitional to Cedar Apple Rust. Yes, of course pls trim the affected leaves and burry under soil because this fungus has capacity to produce different kinds of spores. The spores are wind-borne, so it may contaminate new flushes. Pls treat rest of the leaves with fungicide like copper oxychloride wettable powder dissolved in water or Cymoxanil.