I guess someone could, but I think there wouldn't be much need for an app on how to make coffee, then there is for tea? Well if someone has a cool concept, send me a message, I could code it up!
Speaking as a denizen of the US, making coffee is more complex than we've been socialized to think in N. America. We've been socialized to accept the mediocre result of stale grounds and water that's too cool. (Which makes for an easier time dealing with UL)
I agree. There are tons of interesting ways to make coffee, not all of which require investing hundreds (or thousands) of dollars in fancy espresso machines: i.e. french press vs. aeropress vs. traditional drip filter vs. gold cone, etc...
Cone drip filter. Grinder. (Get a used burr grinder or a good Krups or Braun rotary is good enough.) Whole bean coffee roasted in the past two weeks from a local roaster. Candy thermometer. Pot of boiling water.
If you actually get fresh beans and figure out exactly how much water and how hot it needs to be, the coffee gets really good.