Real-Time GPS Tracker is an app for Android phones that lets you share your current location on the map. It is free and easy to use.

Open Google Play on your Android phone and search for "greenalp", or use this link: Real-Time GPS Tracker on Google Play.

1. Launch the app on your phone and push the start button. Choose a username and password and wait until your phone receives the GPS signal (you need a clear view of the sky).
2. Log in to this website using the same username and password you chose in the app. You should see your location on the map now.

The easiest way is the app's sharing function: send a message to your friends and they just need to click the link to see your location on the map. Optionally you can upload a photo, which is then used as your marker on the map.

The web portal always shows your latest track, comprising a maximum of 1000 GPS trackpoints (network locations are skipped) — older locations are deleted periodically. If you plan to record longer trips and want to keep the complete track, you need the Track Loading feature: as long as it is active the server keeps every trackpoint, lets you download all of them, and shows tracks even past 1000 points. As soon as Track Loading expires the server starts deleting trackpoints again — download them first if you want to keep them.

Yes — if you have configured a keyword in the settings, you can start and stop the tracker by sending it a text message. The tracker only reacts if the message contains the exact phrase.

The RTT2 app's "SMS command" dialog builds the right phrase for you; sending it by hand with your regular SMS app also works. The text has two parts: the SMS password (SMS keyword) configured in your settings, and the command — for a password of "trackme":

• rttpwd=trackme rttcmd=startservice — start the tracker
• rttpwd=trackme rttcmd=stopservice — stop the tracker
• rttpwd=trackme rttcmd=startgps — start GPS (service already running)
• rttpwd=trackme rttcmd=stopgps — stop GPS, keep the service running

Starting the tracker remotely does not guarantee it can send your current location — if data connection is off, or the phone has no GPS signal, it cannot send track data.

Tracking normally needs the phone to be connected to the internet, with one exception: if there is no internet, you can send an SMS remote command and the tracker replies by SMS with the GPS coordinates.

Important: for security reasons this only works if you have explicitly allowed it in the tracker settings ("Allow automatic SMS", in the remote command section). For an SMS password of "trackme":

• rttpwd=trackme rttcmd=tracksms — acquires a fresh GPS fix and sends back the coordinates (or an error if the signal is too weak)
• rttpwd=trackme rttcmd=tracksms lastknown — sends back the last known location instead, without acquiring a new fix, so it answers faster

Real-Time GPS Tracker only displays the most recent track points. If you stop moving, all the points sent refer to the same spot and the track gets shorter and shorter — as soon as you move again, it grows back.

Yes — Greenalp notifies you when the tracked user enters or leaves an area you configure in the web portal. This is a non-free feature; very cheap starter packages are available, see Geo-fencing.

You can send not only your location but also messages — viewers in the portal see your last message (if it is not too old) and can send one back to your phone. Another feature is Track Loading, letting you view your location history; it is a non-free feature, and you can contact support to try it for 24 hours free of charge.

Password recovery is only possible if you have entered your email address in the web portal settings. Please contact Greenalp support to get a new password.

Yes, greenalp.com supports embedding the map into an external site — though there is no guarantee this feature will be available forever. See Website embedding for how it works and how to enable it.

There is a video help section on YouTube. Please also visit the Greenalp Forum.