Hey guys, we launched our app builder Calcapp on Product Hunt a while back (https://www.producthunt.com/posts/calcapp) and we launched paid plans only yesterday. We announced a program today for makers building app businesses on Calcapp (https://www.calcapp.net/blog/2019/05/15/startup.html), enabling you to build products for free on Calcapp.
We support close to 300 Excel-compatible formula functions, PDF reports, Zapier integration and web apps that work offline. Check it out at https://www.calcapp.net. You're welcome to ask any follow-up questions in this thread.