The app freezes at the time of the login if you are using multiple devices at the same time.
The app freezes because the Clock-In/Check-In data from the first device has to sync with the other device when someone just logs in. This happens only when someone logs in to a device, at other times, the devices will stay in sync.
Once you login on the 2nd device, please leave the app for about 3 to 5 minutes to sync the data on both the device. Once the data is synced the app will start working normally without freezing.
Please note this will happen, even if you log in on an iPad and then on an Android device or on two Android devices.