In addition to posting my original query I simultaneously contacted Garmin. For those of you that are interested here is there response:
"Thank you for contacting Garmin International.
The Viago application has been removed from the application store, and is not going to be improved further. Mapping updates will still be released, and technical support for the product will still be available. We will not be updating the application for any future iOS versions. It will still be downloadable from your purchase history in the future.
With Best Regards,
Britton
Customer Care - Map Update Team
Garmin International
913-397-8200
800-800-1020
913-440-8280 (fax) Att: Britton 5948
www.garmin.com
Additional solutions may be found at http://www.garmin.com/garmin/cms/site/us/support/searchsupport"