Patents were invented to make trade secrets public for the betterment of society - for example some enterprising engineer comes up with a method for making super strong steel - just looking at the end result doesn't give you any clue and if the engineer kept it as a trade secret the method might go with her to her grave - thus hurting society. She taking out a patent means that society gets to learn how to do it and she is rewarded for sharing by getting extra compensation from licensing the patent to other engineers.
Location-based reminders is not a significant advance by that definition.... and should not be patentable IMHO. All the necessary patentable advances were in the GPS system etc upon which this simple and obvious idea is built. Makes me sick how much this system is abused.
Doesn't it feel like almost every societal tool has been switched into reverse these days?