It's a wallet where you can invite yourself and your friends to create a "treasury". One person is allowed to spend and others can only see (watching wallets). Additionally, it is also possible to regulate the spending by creating access control. For instance, one is only allowed to spend X amount of bitcoins in Y amount of days.
how exactly controlling access to fund done in your wallet? if your wallet has the total control of the fund, don't expect anyone to be interested in it
you should just implement multisig address with easy interface to coordinate and connect multi users