Well Chromebooks cannot run most android apps unless you manage to recode and hack your computer in order to make running an android app feasible on it.
If you want to run android apps on it, I recommend an emulator such as Bluestacks or Vysor. You can download apps onto your phone to your computer however.
An android app I personally recommend however is...well...I personally have no clue since I never use the play store at all on my Chromebook.