There are two distinct access passwords in MEO™. The first is the app access password and the second is for the optional Syncryption service. Those two passwords can be different and they are independent of each other.
The app access password is unique to each device. That means if you have two devices you can configure the access password with different passwords. It also means that if you change one device’s password it will NOT change the other device's password. The reason for this is, MEO™ is designed to function as an independent app. The other cool thing is that your password is used to create an encryption key for all the data on your device. Without the password, there is no way to make the decryption key to decrypt your data.
The password for the optional Syncryption service, is independent of the app access password. That means it can be different from the app access password. Note, that you use that same password to sign into Syncryption on multiple devices and My Eyes Only® for Mac. When you change that password, it acts just like a Facebook sign-in. If you want to access the account from different devices you would have to use the new password. Another way to think about this is, that the Syncryption password gives access to your Syncryption account on our secure cloud servers. That password works only to access data in once place, our servers. Also note, that if you change your Syncryption password, it does not change your app access password.
Understand, it is possible for you to use the same password for all your devices, your Mac and your Syncryption account, many people do. Understanding the above rules help when you go to change a password.
Lastly, the one set of credentials you need to memorize or write down is your Syncryption password and account login. That way if something happens to your iPhone, you can easily restore you critical data in MEO™, by simply signing into your Syncryption account from within MEO.