These apps are as good as the overall functionality that you require. Goodbarber is probably the better choice overall amongst the two. Goodbarber has more options when it comes to making design changes and also has many different templates you can choose from. Appypie well sucks. The interface for making design changes is very basic so you can just take a basic designer course to learn to apply your ideas using the interface of goodbarber. As far as the backend is concerned there are quite a few options that you can browse through. Creating logins, integration with databases etc are pretty much taken care off. So if your goal is to develop good prototypes for your business idea for basic fitness apps etc. good barber should be fine. You can use good barber possibly for a longer life cycle if you could hire and outsource the work to developers in Eastern europe to add some additional basic functionalities to your app within the platform. At the end however, it will come to the idea and how you want it to be executed. I hope this answers your question. If you have any further let me know.