After successfully download the App, please follow the steps to trust the App before using it.
If your iPhone is currently using IOS 9 or later version, please follow the steps below to trust the WE APPS.
1) Tap Settings > General > Profiles
2) Under the heading "Enterprise APP", tap "Wisers Information Ltd"
3) Tap "Trust Wisers Information Ltd"
4) Tap "Trust"

And then you can use the latest WE App.