The study deals with crowdsourcing and the supporting technologies. The crowdsourcing is becoming more and more popular todays, thanks to the opportunities offered by mobile devices. This paper provides insight into these technologies, and into the work of the open source systems made for this purpose. These systems are the Ohmage questionnaire fill application, the Funf data collection framework, the XMPP technology and the BuddyCloud community platform. In the first part, I'm dealing with a variety of sensor data collection, such as GPS, WiFi, cell information, NFC and QR codes. For the achievement of these, Funf framework and Android operation system were used. In the second part of the paper I present the implementation of a messaging service. In doing so, I present the XMPP technology and the BuddyCloud community application. In connection with the application performance, measurements are made at both server and client side to see if the architecture's ability to serve the needs arise. The messaging framework is further developed, generalized, and independent from business logic, so later it can be reused for other applications. Finally, I made recommendations for further development of the application.