Developer Create account for user.
Developer encourage user to create pin in application.
User want to see deposit address of asset, developer create asset deposit address for asset.
Developer read asset deposit address and show it to user.
User deposit asset into the asset deposit address in external wallet.
Developer read asset of user and show balance to user.
User want to transfer asset. Developer transfer asset for user.
User use application service to add one withdraw address. Developer create the withdraw address for user.
User need to withdraw asset to external blockchain. Developer withdraw asset to existing withdraw asset address.
User want to delete one withdraw asset address. Developer remove withdraw asset address.
User want to change pin code. Developer help to update pin.