On the basis of a competitive and caucus season upon us for the 2012 Republican Presidential race (Democratic race uncontested with President Obama to run for re-election), the iPhone could be a useful guide in helping You decide who to choose. These are applications that can help in the process.
Pocket poll (free) includes all of the candidates, giving their position in a dozen different issues such as abortion, gun control, and immigration. If You want a thumbnail sketch of each candidate, this is the app for You.
Candidate (free) will ask you your opinion on 16 different issues and allows you to take into consideration the importance of each. At the end of the quiz, it will rank candidates (including President Barack Obama and Vice President Joe Biden, as well as the Republican primary candidate) based on how their positions match your answer, and You can click on any potential links to more information.