Your developer can do this. HEre's how we did it:
Install the HRM on a sub-domain - Same domain as Worksuite.
Then, have the dev connect the two databases and add a menu option for HRM in Worksuite. When a user that is logged in clicks on HRM, it would automatically log them in because they share the same database. It works flawlessly.
Yes, of course if Froiden did this themselves it would be easier.. LOL but just providing a solution as I doubt they would actually implement the HRM with Worksuite.