App development to support Linux based Mobile phones
A number of Linux based phones are under development, using PureOS or other Linux based Operating Systems. A Protonmail app written for these mobile phones would provide a privacy/security enhancement for them. The release of the Librem5 Linux based PureOS mobile phone is eminent.
Similarly, a Linux based mobile phone application for ProtonVPN would be a beneficial addition to these phones which have been developed to avoid the lack of privacy/security found in iOS and Google based Android operating systems.
When Will You Release ProtonMail for Actually Secure Devices?
Linux Geek commented
With the new release of the Librem5 phone by Purism, a linux package would be ideal. The easiest to manage multi Linux platforms would be to make said package in a universal package format such as a snap, app image or flatpaks. With such a platform (librem5) it goes hand in hand with Proton's vision of privacy and security.