From reading reviews and comments, it seems there is some confusion about what THIS plugin does. It does NOT create forms (the GravityForms plugin does that), THIS is simply an add-on 'bridge' to send the DATA from the forms you create using GravityForms into your Infusionsoft account so that you can manage those contacts in Infusionsoft.
It does that spectacularly well, and offers some nice features such as adding Tags used by Infusionsoft as it sends the data over, so that you can use those Tags to trigger automated sequences (such as follow-up emails, etc).
It's very simple to setup with your Infusionsoft API key and account subdomain (and even shows you how to find that info if you don't know it). It's very simple to create a "feed" from each of your forms into your Infusionsoft account.
Something that isn't very clear is that if you have fields in your form that are not your typical contact fields, you must FIRST create those "custom" fields in your Infusionsoft contact record setup so that you can THEN map them from your form to those fields as you create your form's "feed".
This would get a 5-star rating from me if the developers would add (as a future version feature request) the option to feed directly into an Infustionsoft-created Form, so that actions that require a Form Submission in Infusionsoft as a trigger can be used - for example to keep consistency in an HTTP Post from Infusionsoft to an external database, or for lengthy chained sequences that use the form-submission-to-landing page sequence.
BUT all-in-all this is a truly great plugin if you just need to send your GravityForms-submitted contacts/data to your Infusionsoft account.