Do you know people in HR departments? That's who you should be talking to.
Ideally before you built your application you would have ran this idea past them and taken their feedback to help determine what to build. I might start there regardless. Even though you've already built it, it would be better to figure out what you should have built before you spend more time or money on what may not be the ideal product.
If you don't know any HR people you need to do whatever you can to meet some. I would call a bunch (cold call) and ask them if they could give you a little bit of time to run some ideas by them. Don't try to sell them at this point, just explain the product and get feedback. Keep doing this until people seem to be really interested in what you are pitching them. Find a few that would be willing to test it for you if you can build that product. Get an idea from them on what they might be willing to pay. Use their feedback for your marketing.