The free plan allows you to use all the features of GigJazz. The only two restrictions are on the number of Concurrent Gigs you can have setup in the planning stage and the number of invitations you can send in a Gig.
The free plan allows 3 concurrent gigs. So, if you just have a few gigs per year, the Free plan is perfect. If you have a small business where you are working with clients and find a tool like GigJazz helpful, a paid plan is the next step.