Put Influenza on your home screen.

It opens full screen with its own icon, like any app, and there is nothing to download from a store. It is the same Influenza you are using now, so it is always up to date and takes almost no space.

Installing asks for no permissions. Location is asked for only when you tap “Near me” or “I'm here”, as on the website. To remove the app, delete its icon like any other.