The paper describes a platform developed by the Extreme Citizen Science ExCiteS group at University College London over the past five years to facilitate online data capture by Citizen Scientists in the context of community science, where local environmental problems are monitored. Responding to user needs, the platform has been developed to be as flexible as possible in terms of the types of data that can be captured -- these currently include numbers, text, video, photography, pull-down lists, multiple selection lists and so forth. Live data feeds and links to social networking such as twitter have also been incorporated. This platform is database-centric, and thus allows capture and storage of data from multiple devices currently Web and mobile in one central location. All map-based data is captured and held in native spatial data format inside the database. To support Citizen Science activity, the system has been designed to allow new projects to be added without the requirement for additional development programming, and an administration tool developed to support this task. Each project is allocated custom themes depending on the project requirements and a variety of 'skins' can be configured to give the website a different appearance in each case. The platform is currently used by over 20 different groups within the United Kingdom -- though mostly for more social and perceptual data collection, rather than scientific. After demonstrating its use in an urban noise study, it is now adapted to use in air pollution studies. An extension to mobile devices Android is also underdevelopment.