Create a simple node.js app that uses your mobile phone to simulate an IoT device and sends live accelerometer data to Watson IoT Platform on Bluemix. If you don't want to do any devOps or coding, try a similar demo app here: (http://discover-iot.eu-gb.mybluemix.net/#/play)
See this Bluemix document Getting started with Watson IoT Platform and a mobile web app
See Step 6 - See raw data in the Watson IoT Platform
See Step 7 - Visualize live data in the Watson IoT Platform
Web app hosted on Bluemix > Runs on phone > Javascript gets accelerometer data from phone and sends via MQTT to > Watson IoT Platform