Yo

Associated With

Yo; individual creator not established by the retained records - creator or operator, brand

Defining Feature

A one-tap push notification carrying the word “Yo”

Status

Historical app - Operating as an app and developer platform in 2014

Overview

Yo reduced mobile messaging to one tap, sending a push notification containing only the word “Yo.”

The 2014 app also connected users with service accounts, turning the same signal into a subscription to alerts from publishers, shops and other services.

Behind the spare interface, its developer API could notify all subscribers or a specific username and directly attach a link. A 2014 challenge also documented location features and invited one-tap service integrations.

Why It Mattered

Yo showed how a deliberately limited interface could serve as both a social signal and a practical trigger. It turned a one-word notification into a flexible connection between users and services without requiring a conventional message.

The Yo Signal

• The app used a short push notification identified as a Yo.
• Subscription began when a user Yo'd a service account.

API Design

• The May 2014 API used a single endpoint for basic sends.
• Services could notify all subscribers or a specific username.
• A link could be attached to the notification.

Developer Challenge

• A 2014 developer challenge documented link and location features.
• The challenge invited one-tap service integrations through the Yo API.

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