Has the Runbox team thought about a mobile app that can be installed and used on Android iOS rather than having to use a 3rd party like BlueMail (which works well) or other built-in apps incorporated into the operating system?
They did not, and I’m comfortable the way this is going, no app installation over Android, just this new thing called Progressive Web App PWA You can find more information over the Blog Runbox 7 Webmail app for mobile phones.
Right now Runbox should be rushing over the No notifications in Android app.
I abandoned MailDroid for BlueMail. BlueMail has CalDav support and also happens to be free. There is no CardDav support at this time, just Google and Exchange. Configuration with RunBox is easy.
Perhaps the best thing RunBox could outside of developing an app (waste of time) is to provide a list of apps that integrate with all of the Runbox services.
I primarily use the web mail client. On my phone, I do prefer an app, but who knows, that may change too.
You can add a shortcut to your home screen when opening https://runbox.com/app/login in your browser.
A small icon with a plus sign should show to the right of the URL, and if you click on that and follow the prompts you can get that shortcut.