Haven't used accountable2you, but if you're looking for a free and effective porn blocker, I can recommend
Simple Blocker (for Chrome). You can create a list of domain names to block, and then can lock down access with a password. This won't allow you to disable it so easily.
Most porn blockers for browsers aren't effective (at least in my experience). Even if they work, you can disable them very easily, which is frustrating. At best, blockers will give you a moment to pause and hopefully stop what you're doing.