You can easily and securely invite someone to your sync account with just a few clicks. To begin, go to Settings by clicking on the gear icon in the menu bar then enter the sync section on top. From the list of buttons select "Share access to my data". It will show you a QR code and a button to send the invite over e-mail.
If the person you wish to share your finances is right next to you and uses an iOS device, have them install MoneyWiz, launch Camera.app and point it to the QR code then tap on the pop-up that appears then agree to open the URL in MoneyWiz. This will not work if Settings.app > Camera > Scan QR codes setting is disabled.
If the person you wish to share your finances is not next to you at this time or uses a Mac, use the share invite over e-mail option. They'll receive instructions on what to do: install MoneyWiz and click on a link.
After clicking on the link, MoneyWiz will open and will automatically start to sign in to your sync account. Here are few more details about this feature:
both the QR code and the e-mail invite include your credentials in encrypted form,
if they were signed into some other account previously, the quick-switch of sync accounts feature will automatically be enabled,
if they had some data entered while in offline mode (no sync user), that data will still be available after they sign out from your sync account,
they will have full access to your sync account, just like you do. They'll be able to create, modify and delete anything. There's currently no way to limit this,
if you ever wish to stop them from accessing your data, simply change your sync password and they'll be automatically signed out, requiring new password.