Open the Watch app on your iPhone
Tap the My Watch tab
Scroll to Available Apps
Find the app you want to install
Tap Install
Wait for the app to download and appear on your Apple Watch
Make sure your Apple Watch is connected to Wi-Fi or your iPhone
Make sure Bluetooth is turned on
If needed, open the App Store on your Apple Watch
Search for the app
Tap Get or the download button
Enter your Apple ID password if prompted