Since last year, I have tried not being dependent upon any single cloud provider for any of my personal data. Getting away from Google Ecosystem(mail, drive, calendar, contacts) and its seemless integration with Android is not easy.
With the help of many open-source projects and their amazing communities this has been possible to an extent. Following are some of the projects that I use:
And of course the underlying technologies used by these projects like Ubuntu, GPG, Git, OSM, PHP, MySQL, PostgreSQL, Nginx etc.
To all the contributors of these projects, I am truly grateful to you all.