If the app is functional and actually useful... which seemed to be the case when the whole furore came up, I'm not sure what past activity/scamming of apple reviews has to do with anything.

He got taken off the app store for those activities, doesn't change the fact that a lot of people find it useful.

Despite his past actions, isn't releasing this as an open source project ultimately a generous act? Many people have paid for this product in the past—ergo it has value—and now, it is free for use and modification.

He's not able to sell it now, so it is essentially worthless. He is now trying to salvage his brand/reputation by this "noble" act. I say we should have longer memory than goldfish when it comes to issues like these.

He also used GPLv3 which Apple hates. They even stick with a ridiculously old version of bash (3.2.57 from 2007!) since it had since began using GPLv3 in subsequent versions.

It's the details that matter. :)

Yeah, I'm not suggesting he's a saint or deserves a parade, but I am happy to have another real-world, full-wrap iOS project to review (whether it's well written or not, I don't know) or repurpose.

Edit: My point is: you say that it's worthless, and perhaps it is now to him, but not necessarily to others.

For a fraud, I can actually use the app I paid for. Who cares about the author? This is a net win for everyone.