Google Wallet received an update, getting adjustments to the UI and some feature tweaks. Most important, is that the explore offers option has been removed completely.
Now Google Wallet provides you to receive information for package shipment statuses on the articles ordered using the Wallet app.
The UI supported some changes also, looking slightly different, with your cards and bank account now handled centrally with a dedicated tab in the navigation menu, combining an account selector and eliminating the admin section now lets you use multiple Google accounts.
The APK is approved by Google and updates your Wallet app, so rather than wait for Google to push the download to your Android devices, you can download and install it now.
The cryptographic signature ensures that the file was not tampered with in any way and is safe to install.