- [Plausible](https://plausible.io/) - **5-eyes** - Not open-source, but privacy-focused web analytics.
- [Fathom](https://usefathom.com/) - Fathom, simple analytics for bloggers & businesses
- Photos
- [Piwigo](https://piwigo.org/) - **9-eyes** (self-hosted) - Self-hosted and open-source cloud photo manager. You can also sign up for an ["as a service" account](https://piwigo.com).
- [Fathom](https://usefathom.com/) - Fathom, simple analytics for bloggers & businesses
- *Help requested!*
- Calendar
- [Lightning Calendar](https://www.thunderbird.net/en-US/calendar/) (Thunderbird)- Developed by Mozilla Foundation and open-source. Integrates into Thunderbird and SeaMonkey.