You can download the Alive app on your Apple Watch using the Watch app on your paired iPhone or the App Store app on your Apple Watch:
1. Using the Watch app on your iPhone
Open the Watch app
Tap the My Watch tab
Scroll to the Available Apps section and find Alive
Tap Install to the right of the app
Wait for the app to start downloading
Once installed, Alive will appear in the Installed on Apple Watch section
2. Using the App Store app on your Apple Watch
Open the App Store app
Turn the Digital Crown to browse apps and collections
To find Alive, tap at the top left of the screen, then type or use Scribble or dictation to enter the name of the app