Smartphones have come a long way, so has the extent of security and privacy issues related to them. We are now increasingly dependent upon smartphones for more than just making that all-important call or send out that text.
A file lock app comes handy in such situations. There are many good ones available in app stores.
Google Maps and others live and active at all times. While, it may seem convenient to have your location settings open for such apps, even others like Facebook, Twitter etc, there may come a time when you don't want others to know where you are.