There is a cool Google Spreadsheet, there is an iPhone, which means you definitely need to create a widget. And the WidgetGrid application will help with this.
Firefox technically supports all the features of PWA, but the installation of such applications in the browser is not available. But it is quite easy to activate this feature.
With the macOS OpenIn app you can customize the opening of links in the app you want. You can also customize the opening depending on the source of the link.
I decided to take a look at Tresorit, a cross-platform cloud storage service with support for end-to-end encryption, and try to understand if it would be convenient to use it.