Adblock will block ads from web pages and mobile apps. Due to how internet domain names are designed, this block is not always perfect. Our service is to point your current configured DNS server to our internal dns cache.
(Ad block is on Firewalla Box, it is done using a DNS cache, and yes your DNS lookup will be very fast, and we didn't even advertise this!)
Windows/Mac/iPhone/Android all cache DNS entries, for example, to flush DNS cache on the iPhone is simply put the phone in airplane mode then turn it off.
Some websites will detect adblocking and prevent the content from getting served. If you encounter issues, you should turn off ad blocking.