There are limited academic activities on the methodological aspects of smartphone research applications. This book chapter focuses on this niche area of research. VeVa (Véleményem Van) is an online / mobile hybrid research panel which has been running since 2013 in Hungary. VeVa is already suitable for online research, and its smartphone research application will be available for panel members from 2015. Download of the application will be part of the recruitment process as well. The VeVa panel aims to convince both recent and future panel members to download and use its research application. An online survey was carried out in October 2014 in the VeVa panel to investigate who is willing to download the research application and why. A survey was conducted to evaluate nonresponse bias with an analysis of those panel members who are not willing to download the application. In this book chapter we analyze the motivations related to application download, comparing app accepters, app rejecters and uncertain respondents. This is followed by a detailed analysis of the three groups to detect differences in their characteristics. We have identified 19 significant variables and found smartphone application usage patterns as the most important explanation. There are only slight differences between the groups in regard to socio-demographic variables and to social and other further analyzed factors.