By completing your Steam discovery queue each day, you can earn trading cards during Steam events (for example, the Steam summer sale). This extension will automate the discovery queue process so you don't have to click "next" on each item to get your trading cards.
Load the extension directory as an unpacked extension in Chrome, or pack the extension and install it locally. Or just install it directly at the Chrome Web Store.
After installing, navigate to https://store.steampowered.com/explore/, where you can set how many discovery queues you want to complete. The extension will complete the queues for you while you do something else—or you can just watch it work if you want. After the discovery queues are completed, a message will display on the last page letting you know it finished.