Apple does not allow apps to silence other apps on iPhones. As such, LifeSaver does not lock the iPhone or block calls/texts. Rather, the LifeSaver app deters phone use while driving. Unless your fleet is using LifeSaver with an MDM (Mobile Device Manager), your iPhone will not lock and you will be able to access other applications. However, if you do use your phone while driving, you will receive violations that are reported to your company and your driver score will be negatively impacted.
Apple does have a built in system that can help to encourage drivers to not drive while distracted. We do recommend using Apple's Do Not Disturb While Driving (DNDWD) feature. This allows you to enable the device to automatically silence inbound calls and notifications when driving. You can find this feature in the iPhone Settings app.