Attempting to integrate task management into an existing application using jira as backend

We are developing an application that has the concept of tasks. We don’t want to rebuild the wheel here and want to use JIRA as the task engine. In the first iteration JIRA would be entirely obscured from our users. In a second iteration our users would be able to ‘takeover/assume’ their JIRA account and use our application as a plugin for the tasking component. Any guidance would be greatly appreciated on how other apps have been able to achieve this or if there is a recommended approach.