I was approached by a group of skaters in Los Angeles who wanted to make a map app for fellow skaters. I jumped at the chance.
I often like working on B2C projects when the audience is a niche because it feels like your work is much more personal for your users.
You are addressing the needs of a very specific set of people and hopefully making life easier for them and their set of problems.
In larger scale apps you are trying to please everyone, stakeholders, the myriad of users and yourself. With these small side projects where the users and the stakeholders are the same demographic you can have a lot more fun not just making a usable app but making an app that brings delight.
These are mid fedelity wireframes showing some ui elements and flare while focusing on the interaction design and features of the product.