There are two distinct access passwords in My Eyes Only® (MEO) and ID Lock®. The first is the app access password, and the second is for the optional Syncryption service. Those two passwords can be different and are independent of each other.
The app access password is unique to each installation of both apps. You can configure the access password with different passwords if you have multiple devices. It also means that changing one installation’s password will NOT change the others. An installation of each app is designed to function as an independent app.
The app access password is used to create an encryption key for all the data on your device.
The password for the Syncryption service is independent of the app access password. That means it can be different from the app access password. The Syncryption password is used to sign into Syncryption on multiple MEO and ID Lock installations. When you change that password, it acts just like a Facebook sign-in.
Another way to think about this is the Syncryption password gives access to your Syncryption account on our secure cloud servers. That password works only to access data on our servers.
Also, note that changing your Syncryption password does not change your app access password.
Lastly, the one set of credentials you need to memorize or write down is your Syncryption password and account login. If something happens to your iPhone, you can quickly restore your critical data in MEO and ID Lock by simply signing into your Syncryption account from within MEO.