fish About Groupr

Groupr is a geomessaging tool - for real-time small-group communication in physical space. The primary interface is a map, showing the locations of the Group participants. You can also send text messages and small images to the Group.

Some examples of when you might use Groupr:

How To Use It

When you first sign in to Groupr you are not in any Groups. There's just you on the map all by yourself. To join a Group, start by clicking the fish button in the upper right of the map. This opens up the Messaging panel, which also has a row of buttons along the top. You probably already found this panel by yourself, since that's how you get to this About page - via the question-mark button. Now, see the button with the school of little fishes? That opens the Groups panel. From there you can find and join a Group.

Groups can be either Public or Private. If they are Public, anyone can see them and join them. If they are Private, they have a password, and you have to know both the name and password to join.

Once you are in a Group, you can see other Group members on the map. Any messages you send are received by the other Group members.

You can be in up to three Groups at the same time. If you join a fourth, it replaces your oldest Group. When you are in multiple Groups, your messages go to the members of all the Groups. There is currently no way to send a message to just one Group, or privately to a specific User. Those features may be added in the future.

The Messaging panel also has a gear button - that opens the Settings panel, where you can change a few of the app's behaviors.

Finally, all panels have a big X button in the top right. That closes the panel and takes you back to the plain old map.

Security and Privacy

Groupr uses SSL only, so data in transit is private. On the server, location and message data is retained only briefly - an hour or so - and is then deleted. User identification data and Group membership data is retained indefinitely.

Groupr does not store User or Group passwords, only hashes. The hashes use the same bcrypt algorithm used on many Unix systems.

Groupr identifies your account via your email address. You use your email address to log in. If you forget your password, you can request a password reset message to be sent to your email address. Those are the only things Groupr uses your email for. Your address will not be shown to other users, will not be the target of marketing spam, will not be sold to other companies. And actually, we don't even store your email address - we store a hash, just like with passwords. We couldn't abuse your email even if we wanted to.


Groupr is a Web App, rather than a Native App. It's really just a web page that is designed to be used from a phone or tablet - small screen, adaptive layout, touch interface. The advantage of this approach is that there's only one version of the app, while with Native Apps you have to write separate versions for each different kind of phone. The disadvantage is that Web Apps can't do everything that Native Apps can do - but this is changing. The web standards organizations and browser makers have been working slowly and steadily to bring more Native App capabilities to Web Apps.

Here are some of the things Groupr does that you wouldn't expect to see in a web page:

Getting your physical location - how Groupr places you on the map.
Groupr can optionally notify you about new messages in your Groups, with a little pop-up alert. This works even when the app is not open.
Notifications can optionally be accompanied by a little vibration. It would also be possible to play a little audio alert sound, but I personally don't like those so I gave it a lot priority.
Page Visibility
This lets a page detect when it's visible to the user. Groupr uses this to clear any pending notifications when the user goes to the page. There are plenty of Native Apps which ought to do this but don't - looking at you, Twitter and Google Play.
Media Capture
Groupr can bring up your phone's camera and let you take a photo to share.

There are still some things that Web Apps can't do. For instance, Geolocation only works when the page is open, while a Native App can continue to track your location in the background when it is closed. Nevertheless I am confident that Web App capabilities will continue to improve, and in the not too distant future developing Native Apps will be considered a waste of time.

ACME Labs / Groupr / About