“Fleeing riot police on foot? There’s an app for that …”
From their website, sukey.org:
Sukey is our name for a set of applications designed to keep you protected and informed during protests. When you see something interesting, you tell us. When we’re confident that something has actually happened, we tell you.
They’re also on Facebook.
And yes, there’s a version that works by SMS, so you don’t have to have a smartphone to use it.