Although the process of usability testing a mobile app is the same as when testing a desktop app, there are quite a few differences in the details. Adjust your test to take account of these differences and you'll be better placed to identify the real problems that real users will have with your app when used in an authentic context.
M. Ames, and M. Naaman. CHI '07: Proceedings of the SIGCHI conference on Human factors in computing systems, page 971--980. New York, NY, USA, ACM, (2007)
M. Ames, and M. Naaman. CHI '07: Proceedings of the SIGCHI conference on Human factors in computing systems, page 971--980. New York, NY, USA, ACM, (2007)
M. Ames, and M. Naaman. CHI '07: Proceedings of the SIGCHI conference on Human factors in computing systems, page 971--980. New York, NY, USA, ACM, (2007)
P. Kelley, M. Benisch, L. Cranor, and N. Sadeh. Proceedings of the 2011 annual conference on Human factors in computing systems, page 2449--2452. New York, NY, USA, ACM, (2011)
P. Kelley, M. Benisch, L. Cranor, and N. Sadeh. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, page 2449--2452. New York, NY, USA, ACM, (2011)