Ideally clients that support the cryptographic infrastructure required would be made allowed clients.
I'm looking at you nylas n1 :) Seriously though.. I get both sides of the coin but shouldn't the customer side eventually take the lead? it isn't as if we are requesting a security downgrade, simply a usability upgrade. If focusing on generating revenue is of importance as stated, this should only add to my argument/plea here. Please..

Maybe adapt the existing web app to desktop using nw.js or Electron? You'd get Mac, Windows and Linux compatibility and use the same APIs as the web client.

any update with this? I would love to take an opensource initiative for this!

Don't make a desktop app. It'll be a massive time and resources drain.

Instead, make a locally installed IMAP/SMTP bridge so people can securely use the client of their choice. An analogue would be VPN services, they provide an installable utility for a customised network connection. Decryption and authentication would happen at bridge level keeping on wire traffic encrypted and safe.

whats going on with this..........anything yet for macbook

I agree, a desktop app (open source and supporting all major OS's including linux) is sorely needed. Today's web browsers are bloated and insecure (html5 fingerprinting in particular is a privacy nightmare).

And who are you to speak for all of us that want to pay something for quality app? Max? And what good software doesn't cost anything? did you pay for computer you use? how about internet is it free? Or you think "free" email providers are really free. You want to demand something and then protest paying anything for it? Go back to using gmail.

No will will NOT pay for it, who are you to speak for all of us? David?

Please do this, make OSX APP. I hate accessing email with browser. Need native OSX APP please. We'll pay for it..

Simply wrap the web app with Electron (http://electron.atom.io/) like Slack does

Any progress? Please keep us updated.

You could use http://electron.atom.io to build a cross platform desktop app for all the OS.

Develop in C# for maximum code reuse, UWP+Xamarin to support Windows 10, Xbox, Windows Mobile 10, iOS and Android natively. 1 billion more Windows 8.1/8/7 devices could have a desktop UI in WPF on top of the shared source. Or a 'Metro' app (UAP) to support Windows Phone 8.1/8 as well. Mac and Linux might also become supported - or they'll at least run C# libraries/websites (inproc?).

what about a Firefox / Chrome extension like MEGA? Would this keep the user data safe against malware coded into the browser?

Have it on my phone and tablet:please make it so I can add it to my desktop?

It would be much better on desktops!

Yes, a mac Protonmail app on a desktop would be great. Just click and open.

Would it ever be possible to access Protonmail from a third-party mail app like Apple's Mail or Thunderbird?

Since this was marked as "planned" by the Protonmail team back in August 30, 2015 and we're now going into the 2nd quarter of 2016, how are we looking on the progress for this desktop app?

I would love this as well since I'm not fond of accessing email via a browser either.