I've been selling wall art & t-shirts for a few years now using Print on Demand services, and I've made some in-house tools to help me keep track of things like expenses & profits, fulfillment times (averages and outliers), and open orders (current status & age in days) which is useful for me because I use different print services for different products. These tools currently work with Printful and Scalable Press, and I'm looking into adding Printify as well.
I am thinking about developing these tools into a service for other Print on Demand sellers, and would love to get some feedback on the idea. Would any POD sellers here would be interested in this? If so, what POD services do you use and what other reporting or features might interest you?