What are some alternatives?
When comparing Crystal and Adblock Plus, you can also consider the following products
BlockBear - Block ads and protect your privacy on iOS with a bear
uBlock Origin - Popular and efficient blocker for Chromium, Chrome, Edge, Firefox, Opera, Safari, Thunderbird.
StopAd PRO - The ultimate ad blocker for Windows and Mac.
Ghostery - Privacy tool for transparency and control
Goodly - Student loan repayment as a employer benefit
Privacy Badger - Privacy Badger blocks spying ads and invisible trackers. How is Privacy Badger different from Disconnect, Adblock Plus, Ghostery, and other blocking extensions?