You just need to check the version history for mobile apps to see what the developers are doing! It’s a wealth of information on new features and changes.

For example here’s the Facebook app for iOS:

  543.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (2w ago)
  542.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (3w ago)
  541.1 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (1mo ago)
  541.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (1mo ago)
  540.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (1mo ago)
  539.1 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (1mo ago)
  539.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (1mo ago)
  538.1 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (1mo ago)
  538.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (2mo ago)
  537.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (2mo ago)
  536.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (2mo ago)
  535.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (2mo ago)
  534.1 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (2mo ago)
  534.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (2mo ago)
  533.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (3mo ago)
  532.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (3mo ago)
  531.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (3mo ago)
  530.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (3mo ago)
  529.1 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (4mo ago)
  529.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (4mo ago)
  528.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (4mo ago)
  527.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (4mo ago)
  526.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (4mo ago)
  525.0.0 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (4mo ago)
  524.1 — Our teams have solved many crashes, fixed issues you’ve reported and made the app faster. (5mo ago)