Hashcoins are used in the Store to buy special Trunks, Time skips, or Liquor. You can also use them to purchase any cards you're lacking if you want to upgrade a Character or Business.
Special Trunks (Gold and Legendary) offer greater chances of unlocking Characters.
NOTE: Time Skips do not affect Lahey's trunk.
TIP: Scroll down to 'Buy Hashcoins' and tap on the 'FREE!' button to see various offers you can complete to earn Hashcoins in Trailer Park Boys!