Yes, provided you have internet connectivity and you log into Boost account linked to your Malaysian mobile number. You can:
1) Top up mobile credit and check its balance
2) Subscribe to internet plans (only if you are an Xpax user)
3) Send money to your family and friends.
4) Purchase Digital Vouchers from Digital Shop but you can only redeem the vouchers from partners that can be accessed overseas such as online shopping/e-commerce portals.