For the past 3 months in my spare time I was developing this list with Awesome Android Alternatives! Please check this out, you might find something useful, or maybe you can help me make it even better. Have an awesome day!

1

Molly (Signal fork)

#Communication #Group Chat & Notifications #Instant Messaging 30 social mentions

2

FluffyChat

Https://fluffychat.im/ is a good Matrix client I'd recommend too.

#Communication #Group Chat & Notifications #Instant Messaging 24 social mentions

3

K-9 Mail

I agree because I need to test it. I am aware of K-9 Mail and FairMail though.

#Email #Email Clients #Calendar 4 social mentions

4

Tutanota

#Email #Email Clients #Enterprise Communication 177 social mentions