Things to improve:
1) Sorting by HP should sort which Pokémon have the highest max HP, not which ones are out of health. Using items already shows you which ones are out of health.
2) Should be able to sell your unwanted/unneeded items to the store for coins.
3) The sightings section... nobody will ever be able to use that. There used to be little leaves that would pop up for Pokémon; that was really nice! Now there is absolutely no way to tell in which direction the Pokémon in the wild might be. Its not even useful to meander around and find them when you have to leave the pokestop areas to do it.
And for a bonus request...
4) Purple shoes!!!
I_Blonde about Pokémon GO, v1.37.2