resources:
- https://web.archive.org/web/20130731024012/http://code.google.com/p/openmobster/wiki/InterAppCommunication
- https://stackoverflow.com/questions/15302093/developing-two-android-apps-and-communicating-between-two
- https://stackoverflow.com/questions/19640703/what-is-the-technology-behind-wechat-whatsapp-and-other-messenger-apps
- https://www.technologyreview.com/s/533081/communication-app-works-without-a-cellular-network/