A critical bug fix is on the way for the problems encountered in v3.9.1
A link to the forum message describing the issue and the solution is here:
The app store listing will once again appear in iTunes once this release is available. We will not be able to bring the app back to iTunes until v3.9.2 is approved because we do not wish to have anyone downloading and using the 3.9.1 update that caused the data loss. Once again, our apologies to those who lost data due to this defect. We pulled the app from the store as soon as we found out about the problem in an attempt to reduce the number of people affected by it.
Personal note from the developer (Barry):
Truly sorry about this poor release. In the 4 weeks that I spent creating v3.9.1 I did not alter my code for the app updates and assumed it was still identical to the previous releases. An external software library was updated (ZIP/UNZIP) and I failed to retest the functions that it provided. Unfortunately it broke the database process where the app downloads and merges public cameras with your private camera data. This is a critical error on my part which resulted in the untested library going into production and causing the data loss. I have worked tirelessly for 6 years on this app and have no excuses for missing such a critical error during testing. I am now working on backup/restore features for v4.0 which will allow recovery of data if a similar problem ever happens again, my fault or not. I hold myself to very high standards and will certainly do what I can to fix both the code and my testing process for future releases.
If your device has recently been backed up in iTunes you can use the iTunes “Restore” option to bring back the data. This knowledge base article from Apple explains:
If you have a second device which still has the data, you can use the import/export options in Live Cams Pro to wirelessly transfer the data and re-populate the device which lost the settings. Click the wrench icon on the main app screen, then select “Import” on the empty device and “Export” on the device with the cameras and favourites.
If you do not have a second device with the data or a backup of the iOS device in iTunes then you will need to manually re-enter the data.