To earn this achievement you need to play Pack Challenges on two different days.
On the map, select 'Pack Challenge' on the far left. Complete the challenge on one day while playing with a dog, and the next day while playing as a cat. The first cat becomes available at level 4 - purchase it through the shop, and pick it in your den before heading to the Pack Challenge.
Unlike the achievement description suggests, you don't need a friend to play these challenges - having friends merely increases your rewards.
Should you have unlocked this achievement already on the WP version, you will need to do it all over again, as achievements between the two versions don't transfer.