If you call their phone, you get referred to their website.

If you go to their online Contact Form and start typing "scam," this will appear underneath:

We are well aware of an individual who has been saying that our organization is a scam. It appears that this individual has gone out of his/her way to say that the IAPWE is a scam and that other websites have posted this same information without making any attempt to verify the accuracy of the information provided. We do not wish to speak badly of anyone, however we ask that you consider that this individual has gone out of their way to provide or create screenshots trying to accuse us of hiding the "secret" identity of our volunteers and saying our organization is a scam without ever explaining what the actual scam is. To us, this seems very suspect. We let everyone see what we offer for free for an entire month without having to pay anything while being able to cancel at any point during that time, as well as any time after the first free month. This would make for a very poor model for a scam. While we cannot tell you who to believe, we can only ask that you not believe everything you read and that you consider your own firsthand experience with our organization as well as the fact that our signup process does not involve any up front payment nor do we collect any credit card information; hence our reason for using PayPal as our payment processor. This alone shows that the information being posted about our organization (all coming from this one individual) is false. The only information that we have collected is that which you provided on our signup form, and, as per the terms and conditions on our website, we will not share this information with any third parties nor have we collected any of your financial information since all transactions were done using PayPal as a payment gateway. >We are an organization based in the U.S. and we are bound by U.S. law. We have made all of the contact information for our organization readily available in case you have any further questions about anything.

I asked them to give some evidence that they were not a scam. They did respond but were very defensive and failed to address any other salient points.

My conclusion, in agreement with others here:

Wouldn't do business with them, scam or not.