Smartphones and apps offer an innovative means of collecting data from the public in surveys. The Netherlands Institute for Social Research | SCP has been engaged in one of the first experiments involving the use of a smartphone app to collect time use data recorded by means of an electronic diary. Is it feasible to use smartphones as a data collection tool for social research? What are the effects on data quality? Can we also incorporate reality mining tools in the smartphone app to replace traditional survey questions (for example by tracking GPS locations of telephone log data)? The report describes a pilot study carried out in the Netherlands by SCP and CentERdata (Tilburg University) in 2011/12 to test the use of smartphones as a data collection method.