Your phone already has this feature for any app. On iOS its called Guided Access and on Android its called Screen Pinning.

I mean people lose their wallets and purses all the time with their physical license in it. If you actually go and read the website or look at the app in the play store, the app doesnt even load unless you enter your PIN or unlock it via face ID or password. It also has a remote wipe featuer incase your lose your phone. Also most phones have lock screens so this seems pretty secure VS a physical DL.

Your comment doesnt make any sense. If you read the website, it says it's a hands off experience. LE cant go through your phone without a warrant. Additionally, depending upon the type of phone you have, you can pin the app to the screen where you can hand them the phone and they are only able to interact with whatever app/screen you pin to your device. If they try to exit out of it, it goes back to the lock screen. On Android its called Screen Pinning and on iOS its called Guided Access. Super useful features.