Someone sends you a .riv file. Finder shows a blank icon. Install Riview, press Space — and it plays. Every artboard, every state machine, every animation, running live in Quick Look before you've opened an app.
Rive animations ship as .riv runtime files, and .riv files can't be opened back in the Rive editor. If you're the developer, the client, or the teammate who only received the .riv, the official route to see or export it is a cloud render queue that needs a $108/yr seat and the original source file — which you don't have. Your file just sits there.
This is the whole model. There's nothing to discover after you install.
No accounts, no telemetry, no analytics — the privacy policy is three paragraphs because there's nothing to disclose. Sandboxed, sold through the App Store, purchases handled by Apple. Keyboard-first: Space play, ⌘E export, ⌘C copies the current frame clean, free, forever.