[9712263]

This phone is basically a Gnome Phone, so mail client will be Geary, which is decent enough. The anbox project is able to port Android apps into GNU/Linux. Though last time I tried, not very stable and crash very often. Whatsapp could be installed. Hope at release the project could be more stable and able to port to Librem 5.

[beatgammit]

WhatsApp isn't open source, and they don't have a client for that chip AFAIK, so getting WhatsApp working would require work from Facebook.

Apps like Signal that are open source will likely be available.