Raising the quality of the Play store is as easy as getting rid of stars
Google play and most other smartphone app stores offer user reviews to let everyone else know how great an app is (or isnt). But the reviews are usually very scattered and dont actually offer much in the way useful info to another shopper. Android is full of really rather crappy apps, and while its less of a problem on iOS, there are bad apps in the App Store as well. What does 3.8 "stars" actually mean to anyone? Almost nothing.
So whats to be done? Its pretty simple actually, just move to a "Yay or Nay" system. Ebay has done this for eons. Every developer would just have a percentage of the positive feedback, and the number of total feedback for all of their apps totaled up and displayed right next the their name on every app page.
That way if a developer has one good app, and 5 bad ones on Google play their percentage will still be low. This will encourage them to drop their bad apps, or improve them, and either way the over all quality of the play store goes up. Also a small developer with just one, good app, has a nice percentage to show off. Moving to a "feedback" system would result in fewer, but much, much better apps. After all there is no point in have 10,000 twitter clients but only 3 that aren't terrible.