...However, there is no one solution that works well for lower level libraries where there is desire to share code between platforms. Kotlin Mobile Multiplatform (KMM) is a player in this place, but it hasn't really caught on. py2many provides an alternative.
A batteries included NodeJS API Kickstater focused on extensability
This is a project based on NodeJS and Koa (and some other libs) implementing a REST API to authenticate users and let them manage TODOs stored in a PostgreSQL database. It's easy to extend and provides you the best developer experience possible with a lot of nifty things already configured. It's meant to be used with a front-end consuming the API like a mobile app or a SPA built with for example React, Angular or Vue.
An MDA(model driven architecture) tool to generate a complete web / mobile app from a UML model. Will generate high quality , best practices compliant code from UML model for all tiers of an enterprise application i.e. presentation, persistence, plumbing