getIdentity allows your application to request permission to interact with a user's Scatter and be provided with an Identity of the user's choosing. You can equate requesting an Identity to signing in with Google or Facebook without a centralized server.
scatter.getIdentity(requiredFields).then(identity => {
//...
}).catch(error => {
//...
})
// The latest scatter-js will also allow using:
scatter.login(requiredFields)