Disabled display of ads; Added free DLC purchase option: Install Lucky Patcher and run it (no root needed, be sure to update to the latest version after running it); In the Toggles, enable Google Billing Emulation and Proxy server to emulate purchases; Install and run the game; Click on Portal Proficiency - Buy Portal Proficiency Add-on; If you did everything right, a window will appear asking you to continue the purchase. Check the box Save to restore purchases and click Yes. For hacked purchases to work correctlybe sure to install the latest version of Lucky Patcher!