Fossify Calendarβ β β β βBasic calendar app that works with your phoneβs local calendars. You can do all the usual things you want to use a calendar for on your phone. Doesnβt clutter up your schedule with ads or vacuum up your personal data.
Fossify Contactsβ β β β βBasic, privacy-respecting contacts app for Android that works with all contacts accounts on your phone.
Gearyβ β β β βReally lightweight but still modern, so itβs a good choice on lower-end hardware. Basic IMAP features, good for most day-to-day email use.
Gmail (Android App)β β β ββWorks well with multiple accounts and display modes, but tracks you more than it should.
K-9 Emailβ β β β βClassic email app for Android: No frills, no ads, no tracking. Supports multiple accounts, phone-to-tablet layouts, and dark mode.
Microsoft Outlook (Android)β β β β βIt works. More stable than the desktop version. Handles mail, calendar and contacts, offers the focused/other inbox view. Tries to keep you in Microsoftβs apps. OK for work, wouldnβt use it for personal mail.
Nextcloud Calendarβ β β β β Self-hosted, web-based calendar that syncs easily with other apps and has completely replaced Google Calendar for me.
OpenTasksβ β β β β Simple to-do list that works great with a Nextcloud server or local storage on your phone.
Thunderbird (Email and Calendar)β β β β β Stable, capable desktop email application, works well with multiple accounts including Gmail, Nextcloud, easy to set up and use but with advanced settings when you need them. FLOSS.
Windows 10 Mail and Calendarβ β β ββNot a bad email client. Snappy, works with multiple accounts. Some issues with Nextcloud calendar and contacts. Of course itβs being discontinued.