We have been using the "San Jose Clean" smartphone app for quite a while now for graffiti abatement in our neighborhood and the response by city contractors has been impressive. It is very simple and quick to use, and importantly graffiti is usually cleaned up within 1 workday of the report.
It looks like The City of San Jose has expanded the applications reach beyond graffiti and park concerns and now there is a whole host of report options available including potholes, streetlights, and animal control among many, many others. We will be trying out its new capabilities and we'd like to hear how successful it is for you. The app is free, takes up relatively little storage, and is compatible with iOS and Android, just search "San Jose Clean" and download.