What you need to know about Vietnam Airlines mobile apps
The iOS apps from Vietnam Airlines will work with all of your Apple devices, from iPad to iPhone
For Vietnam Airlines Lotusmiles Program members, you'll be able to manage your account from the app, though using their website will no doubt provide more functionality
The Android apps from Vietnam Airlines work with all Android phones and tablets from various manufacturers (Samsung, LG, Google, etc.), and Android Wear watches might also be compatible. Perhaps standard practice these days, the Android app offers the same functionality as the iOS app from Vietnam Airlines.
Also take a look at Vietnam Airlines's website by clicking here — you should be able to do what you need there.