I don't have the iSmoke, but anytime I update the iOS I check to see if there is an upgrade for any of my apps. When I recently updated to 11.3, I check for app updates, and I had six waiting to be updated. If I'm having a problem with an app, and there is no update listed, I delete the app, then download it again. Ninety-nine percent of the time, when I do this, all previous data that was stored by the app is usually saved.