Appsemble is described as 'Pick some blocks of functionality you'd like to see in your app, tweak it and you're ready to use or share!' and is an app in the Development category. There are five alternatives to Appsemble for a variety of platforms, including Windows, Linux, Online / Web-based, iPhone and Android Tablet. The best alternative is Crust Low-Code Platform, which is both free and Open Source. Other great apps like Appsemble are OutSystems Platform (Paid), Mendix App Platform (Paid), Aurachain (Paid) and Betty Blocks (Paid).
The Crust Low-Code Platform is an free and open-source low-code tool that allows you to create your own applications with ease. It features an intuitive drag and drop page builder, advanced reporting, access and privacy features, and automation.