As previously said, an Vaultpass app for android is made. it uses the same engine for generating password. Thus, you get the same password from chrome extension and this app. A downside of this approach is that Vaultpass app might feel slower because mobile device has less computing power. Since most apps on mobile device require passwords once for a long time, this might not be a big issue.
It is very inconvenient to input password in mobile device because the small screen and virtual keyboard. To facilitate the use of vaultpass, you can pull down the main screen to copy the password and paste it into the app requiring password.
Mobile device is assumed to be more secure than desktop computer unless it is stolen. Therefore, Vaultpass allows you to save the domain and password type in app in plain text, not encrypted. Password and passphrase are not saved. This might help you to remember the domains and password type you use to generate passwords. Otherwise, this information is nowhere to find and might be forgotten.