Two minutes, once. After this it's just an app on your home screen.
Kip is invite-only. The person who invited you texts you a link — either an invite link or your personal link. That link is your key; keep it to yourself.
It opens Kip's welcome screen with your invite filled in. An invite asks for your first name once — that's how Kip knows who's who.
In Safari: tap the Share button → Add to Home Screen → Add. The orange orb shows up like any other app.
The installed app starts fresh (iOS keeps it separate from Safari), so the first launch asks again — paste the same code or link and you're in for good. From then on, always use the icon: full screen, no browser.