The big button on the Home screen of the Picture Keeper app can say either Start Backup or Resume Backup. They do the same thing, so tap whichever one is showing.
Both buttons run the same backup
Either button copies the photos and videos the app has not backed up yet. The app keeps its own record of what it has already copied — that record lives in the Picture Keeper app on your phone or tablet, not on the drive — so in normal use both buttons pick up where the last backup left off, and nothing that is already on the drive is copied again. (There are a few exceptions, explained below.)
Why the label changes
The app shows Resume Backup once at least one photo or video has ever finished copying on that phone or tablet, and Start Backup until then. It goes back to Start Backup if you remove the app from your phone and put it back on, or if you use one of the reset options that erases the app's backup records (see below).
When it really does start over
The next backup copies everything again whenever the app's record of what it has backed up is cleared, or deliberately ignored. That happens if you:
- uninstall the Picture Keeper app from your phone and then reinstall it, which deletes the record along with the app; or
- choose one of the Data Reset Options that erases the app's backup records; or
- turn on a clone backup — a fresh, complete copy that deliberately ignores the earlier backup history, which you would have chosen yourself in the app. While it is on, the button always shows Start Backup.
- move to a new phone. The record lives in the app on the old phone, so a new one starts without it — unless you set a new iPhone up from the old one, in which case the record comes across too.
In each of these cases the button reads Start Backup, even when your drive already holds a backup. Nothing is lost; it just takes longer than usual. Where a file lands in the same place as before, the app writes an identical copy over the one already there, so nothing is doubled up.
A new phone is the one case worth checking first. If it backs up into a folder of its own — because a new iPhone has a different name, or a new Android phone is a different model — the drive ends up holding a second copy of those photos alongside the first, so make sure there is room for it.
For the short answer on picking up a stopped backup, see How do I resume my last backup?; for the step-by-step version, see Resume a Backup Where I Left Off.
If you need any additional assistance, please contact Picture Keeper support.