Something useful for a small company that is not yet ready for a full time HR person, but which is hiring personnel.
Zenefits Z2 provides a good core of free HR services, including ATS and most employee management functions. Their business model is to have you purchase premium apps and/or benefits through them. Worth a check for your needs.
I am actually developing a web and mobile recruitment interface for small and mid-sized company. I'd be pleased to get your feedback as a potential user !
Consider a virtual HR consultant, which is much more affordable than an in-house HR department. You get the personalized HR management approach that is available only when you need them. I happen to know someone if you're interested.
What are the required features you are looking for in this type of software?