You can't install an iPhone app on a Watch. An iPhone app would need a corresponding Watch app to be usable via a Watch. In the case of ProtonMail, per App Store, looks like they do not have a Watch app, just iPhone/Pad.
You can't install an iPhone app on a Watch. An iPhone app would need a corresponding Watch app to be usable via a Watch. In the case of ProtonMail, per App Store, looks like they do not have a Watch app, just iPhone/Pad.
Just a FYI, ProtonMail is no more secure that any other email provider. When they’re served a warrant by law enforcement, they hand over the data like everyone else. (I have a ProtonMail account too)