There are so many options, but I've selected just a couple for each relevant platform. You probably already have something installed for RSS and calendars already, but if it came with your phone/computer, it's probably not a good option.

About Open Source

While the RSS, ATOM, and Calendar feeds are compatible with Google and Apple software products, it is highly recommended to install better clients for any feeds you wish to consume. Google and Apple software products subject you to surveillance, manipulation, advertising, restriction, and a wide variety of other forms of abuse.

Free and open source software (FOSS) subjects you to none of these offenses, while offering a more complete feature set, verifiable transparency, and much wider compatibility. These software products are free, both in the sense of monetary cost and in the sense of liberty.

If you're still not convinced, just look up the environmental destruction caused by Big Tech. Data centers used 485 TWh in 2025, and it's projected to double by 2030.¹

RSS clients

* Paid

Calendars

Android users should use ICSx⁵ to sync the calendar. This enables calendar synchronization alongside any calendar application.

Due to Apple's extreme hostility toward open standards and software freedom, there are literally zero open source calendar apps for iPhone on the App Store.

Just for reference, there are more than 180 results for "calendar" on the open source app repository for Android.