Using SharePoint Designer 2013 we can now add simple ribbon actions to launch custom workflows
Create your custom List:
This is the normal item display ribbon:
Create your custom list workflow:
In SharePoint Designer navigate to your list | in the ribbon choose Custom Action | and the location where you want the action to show
Name your action and select “Initiate workflow”
Save it | refresh your page and you should now see your new Ribbon Action
Using the Ribbon Action will trigger the workflow to update the task status.