I'm building Starkeep, an open-source serverless self-hosting system that lets you keep your own data and build your own apps that run on your devices and your own AWS account.

https://github.com/starkeep-org/starkeep-core

Starkeep's common core provides file indexing, syncing, access control and more, making apps both easy to create and interoperable. Starkeep is easy to deploy, and its fully serverless architecture minimizes running costs. I'm working on an official Starkeep Photos app as well (https://github.com/starkeep-org/starkeep-apps), built for web and Android so far. Everything is MIT licensed.