Longtime readers of the site will remember ScratchVox, which offered a unique way of sequencing notes on an X/Y grid. It arrived for free, without IAPs, and had some good features like Inter-App Audio. They're planning on releasing a new, completely redesigned version, and are seeking funding on Indiegogo.
I have personal misgivings about crowdfunding in general, and crowdfunding for apps in specific. But these guys are Canadian, so they get the benefit of the doubt and probably won't run off with the money! According to the Indiegogo page you can effectively pre-order a copy for $15, which is 50% off the final retail price.
This looks like a lot of fun, so I hope they reach their modest $5,000 goal. You can see it in action for yourself here. There are also a series of tutorial videos available on the official ScratchVox YouTube channel.