If you are using SalesforceSDK you can write custom method to logout

function logout(){

  var sfOAuthPlugin  = cordova.require("com.salesforce.plugin.oauth");
  sfOAuthPlugin.logout();
}

This method logouts current user

If you are using SalesforceSDK you can write custom method to logout

function logout(){

  var sfOAuthPlugin  = cordova.require("com.salesforce.plugin.oauth");
  sfOAuthPlugin.logout();
}

This method logouts current user.It will securly loggedout the user and flush the stored access and refresh token