Your alerts are yours.

Information Holler processes

Anonymous installation information

Holler assigns a random installation identifier and stores an authentication hash, notification permission state, app version, timestamps, and an Expo push token when notifications are enabled. These values let the service recognize an installation and route notifications. Holler does not ask for a name, email address, phone number, or account.

Alerts and memberships

When someone creates or joins an alert, Holler stores the alert name, optional description, membership, mute state, and randomly generated capability hashes. Private webhook credentials and owner credentials are stored on the creator’s device; the service stores one-way hashes used to verify them.

Notification content

Webhook requests may contain a sender title, message, destination URL, avatar image URL, and creator-defined metadata. Holler's servers store notification events, metadata, delivery recipient snapshots, and delivery diagnostics for about 24 hours so it can deliver the notification and handle retries, and do not provide a server-side notification-history feed. A recipient's private metadata filter is stored with their alert membership and is not shared with the creator or other recipients. Separately, each recipient's iPhone caches the notifications and delivered metadata it received for that alert locally, for up to 7 days, so the alert screen can show recent activity. This on-device cache never leaves the phone and is not accessible to Holler.

Abuse prevention

Holler may temporarily process an IP address and rate-limit counters to protect the service from abuse. Short-lived request counters are removed after about 24 hours, and aggregate daily usage counters are removed after about seven days.

How information is used

Information is used only to operate Holler: authenticate an installation, create and share alerts, deliver notifications, honor mute and pause settings, prevent duplicate sends, diagnose delivery failures, and enforce free service limits.

Holler does not sell personal information, show ads, build advertising profiles, or track people across apps and websites.

Service providers and external links

Holler runs on Cloudflare and uses Expo and Apple Push Notification service to deliver notifications. Those providers process the technical information needed to provide their services under their own terms and privacy policies.

If a notification includes an avatar image, the recipient’s iPhone downloads it directly from the image host. That host may receive the device’s IP address and request details. If a recipient taps a destination URL, the destination opens outside Holler and is governed by that destination’s privacy practices.

Retention and control

Alert data remains until its creator deletes the alert. A recipient can leave an alert at any time. Muting an alert stops notifications for that installation without affecting other recipients. Invalid push tokens are disabled when the delivery service reports that they no longer work.

Holler has no user accounts. Deleting an alert or leaving it removes the associated relationship from the service. For additional privacy or deletion help, use the options on the Holler support page.

Security and children

Holler uses randomly generated capability URLs, one-way credential hashes, HTTPS transport, and iOS SecureStore for private credentials. No internet service can guarantee absolute security, so webhook URLs should be treated like passwords and rotated if exposed.

Holler is a general-audience utility and is not directed to children under 13.

Changes and contact

This policy may be updated as Holler changes. The effective date above will be revised when material changes are published. Questions and privacy requests can be made through the support page.