Häng!?

The Problem

You know this feeling

You want to hang out. Simple enough, right?
Except then you have to:- Scroll through your contacts to find the right people
- Write something that doesn't sound like a group broadcast email from HR.
- Wait. And wait. And watch people leave you on read.
- Feel guilty for "bothering" them just because you wanted to grab a coffee.It's exhausting. So you end up on your couch watching something you've already seen.
That's not okay. You deserve better. Your friends deserve better.

• The Solution

The Solution

Häng?! is stupidly simple — on purpose.

Open the app. Tap the button. Your friends get a quiet little nudge: hey, they want to hang.
That's it. No message to craft. No awkward broadcast. No pressure. If someone's free and feels like it, they know where to find you. Your number hasn't changed.
No overthinking. No performance. Just a tap that says I'm around.

• How does it work?

How It Works

3 Steps to Häng?!

How It Works
1. Tap Häng?! - That one big button. Tap it when you're free and feeling social.
2. Your friends get notified - A simple, low-pressure ping. "Hey — [you] wants to hang." No reply required. No obligation.
3. Someone reaches out - If they're free, they'll text, call, or show up. Through your normal apps, the way it should be.
That's genuinely it.

• Start Hänging now

Privacy Policy

Plain-Language Summary
We know privacy policies are long. Here is everything that matters, in plain language:
-We do not require you to create an account or provide your name, email address, or any personal identifier to use Häng?!
- The only data we store on our servers is your anonymous 8-character Häng code, the 8-character Häng codes of your friends (your blocklist and sent-Häng history), and Firebase Cloud Messaging (FCM) tokens needed to deliver push notifications to your device.
- Your friend names and contact information are stored on your device. Your name is only transmitted when you send a Häng.
- Sent Hängs are automatically and permanently deleted from our servers within 30 days.
- We may process server-side IP address logs for security and abuse prevention. These are not linked to your identity.
- We use Google Firebase (Firestore and Cloud Functions) with EU data residency. Firebase Cloud Messaging (FCM) is a global Google service.
We do not sell, share, or monetise your data in any way.
- You can delete your data at any time by contacting us or deleting the app.1. Identity and Contact Details of the Controller
Controller (GDPR Art. 4(7) / nDSG): The Häng?! app is operated by:
Häng?! – Meet your Friends
Johannes Frey
Brauerstrasse 45
8004 Zürich, Switzerland
[email protected]If you are located in the European Economic Area (EEA) or Switzerland, the above entity acts as the data controller within the meaning of the EU General Data Protection Regulation (GDPR) and the Swiss Federal Act on Data Protection (nDSG).2. Scope of this Privacy Policy
This Privacy Policy applies to:
The Häng?! mobile application for Android (and iOS, where available);
Any associated backend services, including Firebase Firestore, Firebase Cloud Functions, and Firebase Cloud Messaging (FCM);
Any websites operated under the haeng.app domain.
This Policy does not cover third-party services you may access via links from the app, or the data practices of any messaging application (such as WhatsApp, Signal, or SMS) that you use to follow up after receiving a Häng notification.3. What Data We Process and Why
3.1 Data Stored on Our Servers (Firebase Firestore / Cloud Functions – EU)
3.1.1 Your Häng Code
When you first open the app, a random, cryptographically generated 8-character alphanumeric code (your "Häng Code") is created locally on your device and registered with our backend. This code is your sole identifier in our system. It is not linked to your name, phone number, email address, or any other personal identifier.
Legal basis: GDPR Art. 6(1)(b) – necessary for the performance of the service you have requested; nDSG Art. 31.
3.1.2 FCM Push Notification Token
Your device's Firebase Cloud Messaging (FCM) token is stored server-side and associated with your Häng Code. This token is required to deliver push notifications to your device when a friend sends you a Häng. FCM tokens are generated by Google's Firebase SDK and may change over time; we always store the most recent token.
Legal basis: GDPR Art. 6(1)(b) – necessary to deliver the core notification functionality.
Note on FCM data residency: Firebase Cloud Messaging is a globally distributed Google service. FCM token transmission and notification delivery may involve Google infrastructure outside the EU/EEA. See Section 6 (International Transfers) for details.
3.1.3 Friend Relationships: Blocklist
If you block another user, their Häng Code (not their name) is stored in your blocklist in Firestore. This prevents them from sending you Häng notifications. We store only the 8-character Häng Codes of blocked users.
Legal basis: GDPR Art. 6(1)(b) – necessary for the service feature you have explicitly activated; GDPR Art. 6(1)(f) – our legitimate interest in preventing unwanted contact and harassment.
3.1.4 Sent Häng History
Each time you send a Häng, a record is stored in Firestore containing:
Your Häng Code (as sender);
Your name;
The Häng Code(s) of the recipient(s);
A timestamp.
No message content, no location data, and no device identifiers beyond the Häng Codes are stored. This record is used to display your recent Häng activity in the app and to deliver the notification.
Automatic deletion: Sent Häng records are automatically and permanently deleted from Firestore within 30 days of the Häng being sent.
Legal basis: GDPR Art. 6(1)(b) – necessary for the delivery of the service.
3.2 Data Transmitted but Not Permanently Stored
3.2.1 Friend Name (Sender Display Name)
When you send a Häng, the name you have assigned to yourself in the app is transmitted as part of the push notification payload so that recipients can see who is sending the Häng. This name is entered and stored exclusively on your device. We do not store this name in our database. It is transmitted in transit via FCM and discarded server-side after delivery.
Legal basis: GDPR Art. 6(1)(b) – necessary to make notifications meaningful to recipients.
3.2.2 IP Addresses
Our backend infrastructure (Firebase Cloud Functions) and potentially Google's Firebase platform may log IP addresses as part of standard server-side access logging. These logs are used for security monitoring, abuse prevention, rate limiting, and debugging. IP addresses are not linked to Häng Codes or any user profile in our application layer.
Retention: Server-side logs are retained in accordance with Google Cloud / Firebase's default log retention settings (typically 30 days for Cloud Functions logs). We do not export or store IP address logs independently.
Legal basis: GDPR Art. 6(1)(f) – legitimate interest in maintaining the security and integrity of our services.
3.3 Data Stored Only on Your Device
The following data never leaves your device unless you explicitly transmit it as described above:
The display names you assign to your contacts in the app;
Your local friend list (mapping names to Häng Codes);
Your own display name;
App settings and preferences.
We have no access to this data and it is not backed up to our servers.4. Children's Privacy
Häng?! is not directed at children under the age of 16 (or the applicable minimum age in your jurisdiction). We do not knowingly collect data from children. If you believe a child has used the app, please contact us at the address in Section 1 and we will take steps to delete any associated data.5. Third-Party Services and Sub-processors
5.1 Google Firebase
We use the following Firebase products, operated by Google LLC (1600 Amphitheatre Parkway, Mountain View, CA 94043, USA) and Google Ireland Limited (Gordon House, Barrow Street, Dublin 4, Ireland) for EEA users:
Firebase Firestore
Used to store Häng Codes, FCM tokens, blocklists, and sent Häng history. Configured with EU data residency (region: europe-west). Data is stored within the European Union.
Firebase Cloud Functions
Used to process Häng requests server-side and trigger notifications. Deployed in EU regions (europe-west). Processing occurs within the European Union.
Firebase Cloud Messaging (FCM)
Used to deliver push notifications to your device. FCM is a globally distributed service. Notification payloads may be routed through Google infrastructure outside the EU/EEA during delivery. The payload contains only your sender's display name and a Häng Code. We have configured FCM to minimise data in notification payloads.
Google acts as a data processor on our behalf under a Data Processing Agreement (DPA) incorporating the EU Standard Contractual Clauses (SCCs) as required under GDPR Art. 28 and Art. 46. For more information about Google's data processing, see the Google Privacy Policy and Firebase Data Processing Terms.
5.2 Third Parties
We do not share data with data brokers or marketers.6. International Data Transfers
Our primary data storage and processing (Firestore and Cloud Functions) is located within the European Union. However, Firebase Cloud Messaging involves data transfer to Google infrastructure globally, including the United States.
Such transfers are safeguarded by Google's Standard Contractual Clauses (SCCs) adopted pursuant to European Commission Decision 2021/914 and the EU-U.S. Data Privacy Framework, where applicable. For Swiss users, transfers are additionally covered by the recognised adequacy decisions and transfer instruments under the nDSG.
You may request a copy of the applicable transfer safeguards by contacting us at the address in Section 1.7. Data Retention
Data Type | Retention Period
Häng Code – Until you request deletion or the app is uninstalled and the account is deregistered
FCM Token – Until replaced by a new token or you request deletion
Sent Häng records – Maximum 30 days from the date sent, then automatically deleted
Blocklist entries – Until you unblock the user or request deletion
IP address logs (server-side) – Up to 30 days per Firebase/Google Cloud default log retention
Your display name (device-only) – Until you clear app data or uninstall the app8. Your Rights
8.1 Rights under GDPR (EEA residents)
You have the following rights regarding your personal data:
Right of access (Art. 15): Request a copy of the data we hold about you.
Right to rectification (Art. 16): Request correction of inaccurate data.
Right to erasure / 'right to be forgotten' (Art. 17): Request deletion of your data.
Right to restriction of processing (Art. 18): Ask us to limit how we process your data.
Right to data portability (Art. 20): Receive your data in a machine-readable format.
Right to object (Art. 21): Object to processing based on legitimate interests.
Right to lodge a complaint: You have the right to lodge a complaint with your national data protection supervisory authority.
8.2 Rights under nDSG (Swiss residents)
Under the revised Swiss Federal Act on Data Protection (nDSG, in force from 1 September 2023), you have rights equivalent to those listed above, including the right of access, rectification, erasure, and the right to object to automated decision-making. You may also lodge a complaint with the Federal Data Protection and Information Commissioner (FDPIC).
8.3 How to Exercise Your Rights
Because we do not collect your name or email address, please contact us with your 8-character Häng Code (visible in the app's settings screen) so we can locate and process your request. Contact us.
We will respond within 30 days (GDPR) or as required by applicable law.9. Security
We implement appropriate technical and organisational measures to protect your data, including:
All data in transit is encrypted using TLS 1.2 or higher;
Firestore data is encrypted at rest by Google using AES-256;
Access to Firestore is restricted to authenticated Cloud Functions; there is no direct public write access to the database;
Häng Codes are cryptographically random and not enumerable;
We do not store passwords, because we do not require authentication.
No system is completely secure. If you become aware of a security issue, please contact us immediately.10. No Account Required
Häng?! does not require you to register an account, provide an email address, link a phone number, or authenticate with any third-party identity provider. Your 8-character Häng Code is created locally on your device. If you lose your device or uninstall the app, your Häng Code cannot be recovered. A new code will be generated automatically when you reinstall.11. Cookies and Tracking
The Häng?! mobile application does not use cookies. We do not use any cross-app tracking, advertising identifiers (IDFA/GAID), or analytics SDKs that track your behaviour. The Firebase SDK may collect certain diagnostic data as described in Google's Privacy Policy; we have disabled optional analytics features.12. Summary of Legal Bases (GDPR)
For transparency, the legal basis for each processing activity is:
Delivery of push notifications (FCM token storage, Häng records) → Art. 6(1)(b) – contract performance
Blocklist / preventing unwanted contact → Art. 6(1)(b) and Art. 6(1)(f) – legitimate interest
IP address logging for security → Art. 6(1)(f) – legitimate interest
Compliance with legal obligations → Art. 6(1)(c)13. Changes to this Privacy Policy
We may update this Privacy Policy from time to time. Where changes are material, we will notify you via an in-app notification at least 14 days before the changes take effect. The current version is always available within the app and on our website. Continued use of the app after the effective date of a revised Policy constitutes acceptance of the changes, to the extent permitted by applicable law.14. Supervisory Authorities
If you are based in Switzerland, the competent supervisory authority is:
Federal Data Protection and Information Commissioner (FDPIC)
Feldeggweg 1
3003 Bern
https://www.edoeb.admin.chIf you are based in the EEA, you may contact the supervisory authority in your EU member state of habitual residence, place of work, or the place of the alleged infringement.Häng?! – Meet your Friends | Privacy Policy v1.0 | Effective 1 May 2025

Impressum

Häng?! - Meet your Friends
Johannes Frey
Brauerstrasse 45
8004 Zürich, Schweiz
[email protected]