Note: You will lose Safari Cache and Data! Be sure to read the ENTIRE tutorial before starting, as timing is key! You can use ant OTA download that is revoked!
iOS Versions Tested:
11: Ongoing
11.3.1: Confirmed Working
12.1: Confirmed Working
12.4: Confirmed Working
13.3: Does not work
Step 0 (Recommended): Place Settings and Safari on the Second page of your home screen, and leave enough open spaces for the apps you will install via this method. Go to Settings > Safari and Clear Cache and Data before beginning!
Step 1: Open Safari to the download page of the app you want to install. When you press “Install Now” you will get a pop-up prompt, press “Install” again. At this point you want to quickly close Safari.
Step 2: Watch the app that you selected download, just before it changes from “Loading” to “Installing” quickly activate Airplane Mode. If you were successful you should see the app icon on your Home Screen, but don’t open it yet! If the app is greyed out, or doesn’t show the icon, delete the app, clear Safari and return to Step 1. If it was successful, continue to Step 3.
Step 3: With Airplane Mode enabled go to Settings > General > Profiles and “Trust” the developer. After trusting the developer quickly Enable Wifi, "Verify" the app, and Disable Wifi again.
Step 4: After the app is verified proceed to Settings > Safari and clear cache once again. After this you can open the app.
Step 5: ONLY once you are in the revoked app, you can disable Airplane Mode, and use the app normally!
This method is based off the already known Safari/Airplane mode glitch for ALREADY INSTALLED apps.
Based loosely off the tutorial posted by iOSGodsMember54 and refined!