My Find My Friends app hasn't been working on my iPhone 4 for about a week now.

My Find My Friends app hasn't been working on my iPhone 4 for about a week now. Previously to this past week it was working great. Now, whenever I open up the app it stays open for about 2 seconds and then instantly closes out. This happens every time. Anyone else having the same problem, know if it is just a current glitch with the app, or have any solutions on fixing it? Thank you.