Check that the operating system on your device is up to date. If there are any updates available, update the OS first and then try accessing the Tradify app again.
The same applies whether you are using Android or Apple mobile devices.
If the OS is up to date, then try reinstalling the Tradify mobile app after completely uninstalling it first. If the problem still persists then please contact the support desk by emailing firstname.lastname@example.org or click here to contact us. Confirm the OS version on your device and details of any errors you are encountering. Screenshots are very helpful in pinpointing the issue.