How many times have you been reading an article on your phone, only to be interrupted by an ad that jumps up in your face? Sometimes you can dismiss them, but all too often when you try, either through clumsy tapping or devious design, you end up on some other website. Thankfully, there's Crystal; an ad-blocking iPhone app that cleans up websites and make them load faster, to boot.

Crystal is available for .99 in the iPhone app store and is designed to work on both iPhone and iPad. Once you've downloaded it, you activate the app by making some changes your iPhone's settings. Then you browse the Web normally, just without ads.

Using Crystal
On its own, Crystal isn't much to look at. The app's main page includes instructions on how to activate its ad-blocking powers, and there's also a link to your Settings app. A handy FAQ is available on an outside website. It's not until you launch Safari that you see Crystal at work.

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When testing iPhone ad blockers, I use the Safari developer tools on both the iPhone and iMac. Just like a desktop browser's Web inspector, this lets me view websites' vital statistics. When testing, I reload the mobile pages I want to test without cached information and average the data.

For this test, I used an iPhone 6 Plus. I chose this device because it's a top phone, and also because I've never used a phone that is large enough to double as a ping-pong paddle.

With Crystal installed, I observed iOS Safari loading my test page (PCMag's home page) in 20 percent less time. My test site also loaded 43 percent fewer resources, which include fonts, frames, and images. This led to a notable 34-percent reduction in the data loaded in order to run the site. Lastly, Crystal reduced the number of cookies loaded by the site by 33 percent.

Crystal's effect varies from site to site; some have more cookies or elements to begin with. For example, I loaded CNN.com both before and after installing Crystal and the results were dramatic. The site loaded faster and required fewer resources, and the ad blocker took an extensive list of cookies down to just two.

It's difficult to compare ad blockers, because websites frequently load different content for different visitors. But looking across my data, I found that Crystal performed better than Adblock Plus but was bested by 1Blocker. It's still a strong contender, however.

In addition to all that, Crystal's developer says that the app can improve battery life and protect your privacy by preventing data-hungry trackers from monitoring you online. For now, these are outside the scope of my review.

Probably the most important feature provided by the app outside of ad blocking is the ability to report broken sites. Crystal provides a form where you include the URL and a brief description of the problem. Buttons at the bottom let you select whether Crystal has caused a problem with a site or if ads on the site weren't blocked properly. This is very important, because ad blockers sometimes prevent websites from behaving normally. Letting the developer know about these problems will hopefully make the experience better for everyone. You can also report broken sites to Crystal directly from within Safari using the Share Sheet.

Note that some sites are attempting to punish or otherwise dissuade ad blocker users from, well, blocking ads. Unfortunately, Crystal can't do much about that.

Soon to Be Acceptable
Crystal currently blocks all ads, every time. However, that will be changing in the future. The developer has promised to include a user-maintained whitelist of ads that allows you to decide which sites not to block. I've only seen that feature available in 1Blocker, and I'm glad to see it coming to Crystal.

The new version will also conform to the Acceptable Ads initiative, which allows some ads to appear, provided they comply with a code of conduct. In some cases, money changes hands but the organization says that it isn't a pay-for-play arrangement. Crystal's developer says that users will be able to deactivate this feature if it's not to their liking. 1Blocker, by contrast, doesn't have an Acceptable Ads option.

Crystal Clear
Ad blockers have been around for a while, but a longstanding moral debate has flared up around them again since Apple announced the company would allow them on iOS. Some argue that people have a right to avoid ads, and others argue that people have an obligation to not block ads on online content that's ad-supported. I'll only add that I think it doesn't do companies credit for them to say that they can't find an innovative solution to make money and not annoy visitors. 

For its part, Crystal blocks ads with ease. It makes sites load faster and look better, and it treads lightly on your data plan. It's also free, installs easily, and doesn't look too terrible sitting on your home screen. It absolutely delivers on its promises, and makes it easy to report broken sites. It's a great app and second only to 1Blocker, our Editors' Choice for ad blocking on the iPhone.