Maybe you were shopping for a new tent recently. You clicked around REI's site, did an obligatory Craigslist search. Eventually, you wound up on Amazon, because everyone winds up on Amazon. Perhaps you added a few tents to your Wish List. Then you left that part of the Internet, and surfed somewhere else. Facebook, probably. Tumblr, maybe. WIRED.com, definitely! And suddenly, you noticed one or two or all of these sites trying to sell you a tent you'd just been perusing. Then you went to Facebook and saw another tent right there in the middle of your News Feed.

At this point, you probably know why that happened. Some unknown entity was watching you browse around tent websites, figured out that you're really into tents, then told an advertiser, "Hey, this person is really into tents." This is how the web's media companies make money: Tracing your trail across the consumable web as bots follow you and take notes and report back to the advertiser overlords. It's creepy, sure, but sometimes convenient. You are in the market for a tent, after all.

The web is loaded with weights. Not all of them ads, but all of them weights.

Internet advertising is still evolving, but one constant remains: ads specifically targeted to you make more money for publishers, so it is in their interest to fill their sites with those ads. However, those ads are murder on the speed of a page, turning a lightening-quick load time into an eight-second slog. It's worth noting that ads aren't the only thing to blame for this. The scripts that track you and peep on your tent-shopping load along with the page, and slow it down too. But wait. There's more. Article comments often are hosted by third-party services like Disqus and Facebook, and—yep!—they drag things down too. So do fancy fonts. Turns out the web is loaded with weights.

You're not powerless here. You have many choices for dealing with this. People have long used ad blockers and content blockers on desktops and laptops. That ability arrived on iPhones and iPads this will with the arrival of iOS 9. For the first time, developers can write extensions for Safari that stop ads, scripts, and other page elements from loading. It's obviously something people really want; content-blocking apps skyrocketed to the top of the App Store almost immediately.

Before you start downloading, there is one very important thing to understand: By blocking ads, you are depriving content publishers (like us, hello!) of advertising income and insights into what readers want. To better understand the flow of money and information between readers and publishers, check out WIRED's cover story on the economics of online publishing. Using Buzzfeed as an example, the story breaks down the profit margins of display ads, explains native ads, and explains the many tools, from headline optimizers and social prediction technologies, publishers use to attract your attention. All of these systems rely upon user tracking, the same tech content-blockers fence off. Learning what you like to read helps content providers serve better ads and provide content you'll actually like. But at the bottom line, ads keep the lights on. Content providers like WIRED are businesses, after all, and if you aren't going to pay for the content directly through, say, a subscription, we've gotta pay the bills somehow. It's telling that one prominent app developer has pulled his top-ranked content blocker, Peace, from the App Store because his independent-publisher friends raised concerns about the impact Peace might have on ad revenue.

There are other concerns, too, like the fact that content-blockers block more than ads. Fonts, comments, images, various elements—all might be axed. Removing these things messes with websites' carefully designed layouts, and things may break. So please be judicious!

Here are a handful of content-blocking apps new to iOS 9.

Lets you block ads, and disables tracking scripts. The basics are the same on many of these apps, but Crystal comes packaged in arguably the nicest UI of its competitors. Though that matters very little since it just attaches itself to Safari, allowing you to return to the web, minus common annoyances. Crystal, like other content-blockers, will save you data and battery life. It costs $1.

More of the same! Purify is $4, and gives you the ability to block images, scripts, and fonts from infiltrating your web experience. Everything will also be faster.

Here's another $1 option. Blockr lets you hide almost anything: cookies, cookie warnings, ads—technically, everything. If you have a terrible connection, you can use Blockr to opt only for the bare minimum, stripping a page of any media files that might be dragging things along. It should go without saying, but: still faster.

This is one to watch for because the iOS 9 version is currently still under review at the App Store. Hide & Seek works a little differently in that it blocks the code that tracks your web searches. If you are a Gmail user, you might want this—when you're logged into Gmail, your web searches are associated with your Google ID. Hide & Seek lets you search Google privately without having to log out of any other services. It does the same thing for Bing searches. The FAQ is recommended reading.

Peace

Gone! The most popular of the content blockers, this one built by Overcast creator Marco Arment, has been removed from the App Store by its author. Peace is included here because if you've already bought it, there are two things to know: It will keep working even though it won't be updated, and you can request a refund if you'd like.