79 votesAdminMicrosoft (Admin, Microsoft) responded
The app respects a user’s mobile device policy with regards to simple PIN, complex PIN and encryption. Can you provide more details about your mobile device policy?
An error occurred while saving the commentSam commented
Same problem with Android phones I tested. I enforces the user to have a more complex pin (alphanumeric with special characters). The mobile policy is set to use a 4 digit pin and works on iOS. I had to finally uninstall the app.
Also there is no available widget for the app which makes it less usable.