Today Apple released a patch, iOS 9.3.1. This fixes an issue where many links in programs wouldn’t work or could crash apps when tapped. While the number of people affected by this was very small, this small group found it to be an extremely annoying bug that left their phones almost unusable. If you have this bug go ahead and download the update, but if this bug isn’t something you’ve got then there is no need to rush out to install.
To install go to Settings > General > Software Updates.