Can I launch an iPad application in a different locale than what iOS uses? My iPad 3 is configured in French for the family but I prefer my apps un-translated. Is it possible to force an application to launch in a specific locale? Is it feasible without a third-party tool?
The short answer is that this is, unfortunately, not possible with the default install of iOS. 

It is always possible that there is a jailbreak hack that allows this, but that would probably fall under the "third-party tool" category.