Proton Calendar

by Proton AG

Secure, encrypted calendar for your Android devices.

Calendar

by Fossify

Plan events, reminders, widgets, holidays, and recurring schedules with local calendar data.

Calendula

by Jean-Luc Makiola

A modern Material 3 Express calendar for Android.

Another Widget (azuo fork)

by azuo

A widget app for Android devices, providing various widgets for displaying weather, calendar events, and other information on the home screen.

Suntimes Calendars

by Forrest Guice

A calendar provider add-on for Suntimes.

jtxBoard

by TechbeeAT

jtx Board allows you to manage your Journals (like meeting minutes), Notes and Tasks in one Android app.