Ex-Instagram engineers' photo app Retro raises $21M to grow friend-centric sharing

Retro, a photo-sharing app built by former Instagram product engineers, has raised over $21 million in Series A funding, according to an SEC filing. The app lets users privately share photos with friends, create shared albums, and use features like recaps and rewinds, without advertising—instead relying on subscriptions. Since its 2023 launch, Retro has been downloaded about 7 million times, with in-app spending surging more than 460% in the last six months.