While all the hype is going on about SMTH, students here in the Netherlands have their heads down and are focusing on their science.
The number one SMTH competitor is Catchy, and you can read about how it works in this paper:
Rijnboutt, Eric, Hokke, Olivier, Kooij, Rob, and Bidarra, Rafael. 2013. A robust throw detection library for mobile games. Proceedings of Foundations of Digital Games (FDG 2013).
http://www.fdg2013.org/program/posters/poster14_rijnboutt_etal.pdf
The Catchy team created Catchy as the final thesis project in their undergraduate Computer Science program at Delft University of Technology in the Netherlands.
Rumor has it that the Catchy app was such an irresistible hit that they had the whole committee standing around playing Catchy as they defended their thesis (...a happy end to a theoretical discussion on assumptions concerning initial accelerations).
You will notice that the thesis is dated June 2012, so if you called Catchy the original SMTH you would not be factually inaccurate.
Which one is installed on my own phone? In the choice between SMTH and Catchy, I go for the game that the science geeks play.
Oh, and in case in addition to the scientific paper, you also wanted the download link:
https://play.google.com/store/apps/details?id=nl.orbitgames.catchy
