Moola: Accept credit card payments in ten lines of code.
moolarb.com
moolarb.com
The alternative to your product is using something like Gumroad (https://gumroad.com/) or building against the Stripe API directly, which is well-known for being gloriously simple. Your job is to show developers that using your micro-framework is significantly better than doing a simple integration of the Stripe gem into a framework they already use.
My advice would be to show all of the screens that Moola autogenerates to really demonstrate the added value you're providing. Better yet, create a screencast going from download to deploy in 60 seconds.
From a technical perspective, I'd also recommend using a YAML file to store the configuration settings in one place, making the process even easier. Good luck.
Re: YAML configuration, that's a good suggestion. I wanted to keep the footprint lean and uncomplicated, so I figured swaying away from config files in favor of Sinatra settings was consistent with that philosophy. YAML would be effective for environment-based configuration.
Thanks again!