greenhopper

I'm getting started working with the JIRA REST API. I've learned how to get all the issues assigned to the current user: rest/api/2/search?jql=assignee=currentuser() ...now I am trying to filter those by the current sprint. I think this functionality is provided by the JIRA Agile (Greenhopper) plugin, but I can't find any documentation for it. I came across some interesting data which appears to be the identifier for the sprint that the issue is assigned to: customfield_10005: [ "com.atlassian.greenhopper.service.sprint.Sprint@3094f872[rapidViewId=30,state=CLOSED,name=Sprint 2014-06-02

We user JIRA for bug tracking and release management and we have started using greenhopper for project management inside of JIRA but one thing that it lacks is the idea of user stories versus tasks in those users stories. Does anyone recommend other task board like agile project management tools that fully support users stories and tasks as well as being fast and simple to user. I started looking at targetprocess so if anyone has feedback on that specifically it would be great as well. TargetProcess is the least intrusive project mgmt tool I've used. A common anti-pattern for Scrum and XP