The blue ring around an avatar indicates the amount of time left in the user's Glympse. When the time runs out, the user's location will not be updated on the map.
If 1 hour or more of the user's share time remains, the entire ring is filled with the light blue color.
Anything less than an hour, the ring will begin to countdown. For example, 30 minutes remaining will result in half of the ring filled with light blue.
When the Glympse expires, the ring will be removed from the User's avatar.