Ok, so I followed the instructions in this thread completely and Gas Cubby either crashes or starts up as if there is no data.
I was using the free version of Gas Cubby but had problems with restoring the phone using a backup when I upgraded to iOS8.2. As I said, I followed the transfer instructions and even ended up buying the paid version of the app thinking that might be a problem. Still, no go. Gas Cubby either crashes (looks like it launches but then immediately disappears again) or starts up as if there is no sqlite data file.
Any ideas on what can be done? Having been tracking all my service records with this great app for years but now I have no idea what services need to be done and when.
Well, I figured it out! I had an encrypted backup so iPhone Backup Extractor was extracting corrupted files. Instead, I was able to use a new version of iExplorer which can access encrypted backups (it still needs a password though) to access the sqlite file. Everything now works!
Also, the link I posted above was wrong, this is what I was referring to originally.