Best tools for small HR team at startup?

What are some helpful tools (both free or paid) for 2-4 person HR department at a startup?

The Resumator - Complete HR tool that allows you to post open job, coordinate interviews, etc.

Keas - Lower healthcare costs by using gamification to encourage activity and nutrition.

Work.com - Platform for real-time employee-performance management, review, and feedback.

TribeHR - Complete solution like The Resumator. Recruit and track potential hires, see a company calendar, and monitor employee profiles.

Expensify - Lets employees scan their receipts with a phone and sync it with their digital report or credit card account.