Appwrite is an open-source, self-hosted alternative to Firebase that provides developers with all the core APIs and services required to build any kind of modern software no matter the platform. Appwrite aims to make software development fast, simple and most importantly, enjoyable. Appwrite integrates with Web, Android iOS, Flutter and any server-side language.
In essence, Appwrite takes care of all the things you would typically need to build from scratch, saving you the complexity and time to focus on your application.
You can read more about the recent funding round here https://hazardlights.net/2021/10/26/our-investment-in-appwrite/