You couldn’t download William Hill application directly from website. So, you should install it from Google Play or download APK file.
To install it from Google Play you should have an account with United Kingdom as a country in payment method. Here is an official instruction (at Google Support).
How to install William Hill *.APK:
- Download *.APK file
- If you see notification – Click on “OK” to keep this file
- Open it
- If you see another notification – Click on “Settings” – Allow to install apps from unknow sources – Back button
- Install William Hill Android Application