If you lost your iPhone, or accidentally deleted the app, here is what to do to recover your data.
First, if you’ve been backing up to iCloud, first assure that yo do not overwrite that data. If you reinstalled the app already, go to More > iCloud, and turn “Auto Save” to off. You can then tap on your previous backup to install the data from iCloud back into your new installation.
If that doesn’t work, you should try to get the database out of your iTunes backups. Do this right away before you try to sync your iPhone again, which may overwrite the backup.
Here’s the free program called iPhone Backup Extractor that works on the Mac.
Here’s another version that works on several platforms.
Your goal is to extract a file called Meter.db from your iTunes backups. Note that you’ll want to grab a version backward in time a bit, since you may have synced your iPhone since then with the empty Meter.db.
Once you’ve extracted the Meter.db, use iTunes File Sharing to replace the Meter.db with the one you just found. Here is a knowledge base article on iTunes File Sharing.
Lastly, if you’ve been using Email Updates or social services to share your data, there may be KML files on our servers you could re-import.