Hardest Game Ever 2 joins the top free Android app this week at No. 10, according to research from Google Play. The gaming app from Organnose Studio measures users reaction time through quick puzzles.

Below, we’ve listed the top free Android apps of the week. The list links to Google Play’s research about the individual apps, including user reviews.

As part of Mediabistro’s Media App Summit which took place last year, we spotlight the top free apps every week–helping our readers discover, enjoy and analyze successful content.

Top Free Android Apps of the Week

1.  Facebook for Android

2.  Candy Crush Saga

3. Pandora

4. Instagram

5. Facebook Messenger

6. Skype

7. Netflix

8. Bejeweled Blitz

9. Subway Surfers

10. Hardest Game Ever 2