Pam Bowling of Backyard Farms and known as "Farmer Pam" has long been known to frequently give away little brown paper bags containing 'seed bombs,' little balls of dirt, a little compost and seeds also known as 'seed grenades.' With a smile, she encourages you to 'bomb away' wherever you think a place needs a little help with flowers or edible plants.
It's doubtful that we need an electronic intervention for this simple, low-tech way to spread vegetation, but LA is far from Tallahassee. There, a group known as Greenaid has launched this website where you can purchase seedbombs by the pound that are packaged in recycled cardboard paper towel tubes and--wooden slingshots.
You can log where your seed bomb was deployed or find optimal locations for deployment on the website map (the map interface is a little wonky).
Plus, they have vending machines that look like gum ball machines to dispense individual seed bombs. And they have an iPhone app Greenaid iOS app) that allows you to view locate Greenaid machines near you and find the best place to throw seedbombs.
Or you could just ask Farmer Pam.