Anyone tried out SnapChum for unfollowing Pinterest users on Android?

I have not used it, personally I am scared to install it. Just wondering if anyone else had given it a go since it was the only app I found in the play store that says it does this.

I also found an online site called pinfollow. It has a popup for pinterest authorization but is that safe to allow? I am conceed about my account getting from either one of these services. If you have another suggestion I am all ears.