The startup app: validate the idea, don't build everything
Around three universities and the technopark, a great many app ideas appear every year. The most common mistake we see is trying to build every feature in the first release. Every screen written before you know what users actually want is a cost you will later delete.
For startup apps we first define a single core flow: the shortest path for a user to open the app and see value. That path goes to the store, real user behaviour is measured, and the next features are chosen from data. This protects both budget and time.