Lockbox by GEE Technologies

Both my husband and I have our lockbox app backed up to icloud. When we updated to iOS11 we can no longer access the LockBox. We get the error message that the developer needs to update the app. Can't figure out how to get a hold of the developer so I figure I would ask here.....Anyone figure out how to access the backed-up data on Icloud so I can at least open the file so I can see my user name and passwords?? or is there a way to export the data even tho the app won't open???