First have a look onto the main screen of lggr.io:

As you can see the main purpose of lggr is the aggregation and display of centralized syslog messages with the ability to filter by source host, priority or time range.

You can search for any part of the message by entering your search term in the upper right corner.

To see the complete message just click on the line to get that popup dialog.

You can filter by severity level. Click on the warning label and in combination use the current hour view to be up to date.