The general purpose of the Arweave-SMT is to allow developers to create and configurate their own proving webservice (like this one) that tracks for the chosen smart contract events and gives neccessary proofs to smart contract users. This will be implemented in the next release. See also previous one.
The purpose of this demo is to allow users to play with one already created proving web service that interacts with one already deployed (on Ropsten network) smart contract that uses sparse merkle tree logic. The demo contract is ERC20 token that doesn't store balances, but only merkle root of all data. In this way to check the balance or transfer tokens you need to use this proving service for getting proofs and other required values.
Firstly, You need to login with your arweave address. After that you'll get information about demo contract.
Next, you need your MetaMask be opened and network should be switched to Ropsten Test Network.
Waiting for login...