Backing up is the best way to protect your Kinsa data should something go wrong or if you're simply migrating to a newer model.
You don't need to create an account to use your Kinsa thermometer, but this also means that your data can't be redownloaded if you delete the Kinsa app or reinstall the Kinsa app on your new phone. If you delete the Kinsa app, it will also delete all of the data inside, including your profiles and entries, such as temperature data and recorded symptoms. This cannot be undone.
Instead, we recommend that you backup your Kinsa data by making a backup of your whole phone. This will ensure that if the worst happens, everything will be recoverable, including your Kinsa data. Follow the guides below to make sure that you never lose your valuable data.
The best way to backup your Kinsa data is to make a backup of your entire iPhone, either with iCloud or iTunes. Whichever option you choose, all your Kinsa data (along with all your other apps too) will be safely stored in case of accident or upgrade.
To perform a backup with iCloud or iTunes, follow Apple's Help Article on this topic: How to backup your iPhone
You can back-up your Android device to your Google account, and there are also a huge variety of apps designed to help create easy backups on your computer. Look up some tips on how to create backups of that software version by Googling “backing up an android”. You may need to include your OS version in the search as well.