The privacy window is a feature of the browser itself, not a separate app. Just google on how to activate it for whatever your favorite browser is.
Just go to “file”. Click on it and you will see “open new pruvate window”
I am asking about the apps that HImom mentioned. There are several.
Safari has a privacy feature, including the iPhone version. If you just want to avoid cookies I’m not sure why you’d need anything more. As you mentioned, I’d be wary of trusting privacy features to anything other than a major vendor.
If you are booking through Expedia etc. make sure you only login into your account when you are buying, or you will get a mesage that the transaction did not go through because the price changed.
I think they are getting more sophisticated than simply plastering a cookie or two…
Do the cookies change the prices on the airlines’ websites? Or only if you log in? What about if you’re using frequent flyer miles to buy the ticket?
One tip for parents of sophomores/juniors who might be doing college trips with their kids and live in an area served by Southwest - it may be possible to earn a Southwest companion pass depending on your circumstances. I accidentally got one a couple years ago and used it for a couple of campus visits with D, and also brought her along on a business trip or two so she could see the sights while I was working.
You need 110k points to qualify. But by signing up for their credit card and spending 1k in the first 3 months you get 50k points right off the bat (sometimes it’s 40k, read the fine print). If you have any major purchases (appliances, car, etc) charge them to the card. And of course flying Southwest helps. If you’re on a tight budget this will not work for you, but for those that spend a decent amount each year and travel a little bit for work, the points can add up quickly. (You can also charge tuition and room/board, but colleges charge a hefty fee for that.)
Anyway, it was accidental for me because I just happened to sign up a Southwest card, flew a bit more than usual for work, and charged a few big expenses (including a chunk of a new car) on the card. Of course you should never charge anything you don’t plan on paying off immediately, but that’s a topic for another thread. We didn’t use it nearly as much as I wish we had due to the accidental timing, but hopefully a few out there can take advantage of it with some planning and play the airline’s game to their advantage.
I like having the browsing history for many things- only want to use private for flights. Hence the interest in the app
I use Private Browser iPhone app by Savy Soda. I don’t put in any payment info. When I’m ready to purchase, I switch to my desktop computer that I haven’t searched for flights on and go straight to United’s website to buy my tickets.
I just want to thank those who took the time to mention and explain the ‘incognito window’ in chrome. I didn’t know about that and it’s so easy to access! Will definitely be using that from now on when working on flight purchases. Love CC! 
What I find infuriating is that the same transcontinental flight tickets are sold at two completely different prices depending on whether they were booked from Europe or the US.
This is less common than you might think. More often than not, that plane still has to be there at the destination to pick up passengers for the next flight.
It matters whether you’re arriving or departing. Airports have departure taxes that get tacked on to the ticket price. Two cringe-worthy, expensive airports: LHR & FRA.
Flying out of Heathrow costs ~179 bucks per passenger. Frankfurt airport departure tax is ~120 bucks. It’s gonna to a helluva lot cheaper to land in those airports than to depart from those airports.
Plus, airlines make plenty of money on cargo. Passengers aren’t their only revenue source.
My favorite is that it is almost always cheaper to connect on international flights, even if you take the exact same planes. Non-stop carries a big price premium. We usually drive a few hundred miles to Toronto where airfares have lower base prices, security fees, and airport parking costs. Even after you consider the drive, the net pricing is about half of nearby US cities.
Is there any evidence that cookies are used to present different airline pricing to return visitors? Can someone point me to some?
Interesting reading: https://www.theguardian.com/commentisfree/2016/dec/06/cookie-monsters-why-your-browsing-history-could-mean-rip-off-prices
They are getting even more sophisticated than that - specific searches coming out of a specific location are usually attributable to the same user. Betcha there are no two people in Marysville WA searching at 11:30 pm at night for a flight from Seattle to Dushanbe… 
Thanks, @doschicos . Interesting to me that they said they could do it using cookies, but didn’t have any specific evidence of it. And Uber’s surge pricing is designed to get more drivers out to meet the demand, not the opposite, so I disagree with that premise in the article.
Most of the evidence I see of user-specific pricing benefits the consumer – as vendors know they want to keep you. Airlines need to sell their seats and they really don’t care who fills it. I think the idea that there is an algorithm that says “hmmm, this guy was just here, he must really want this seat, let me clip him for $50 more” is not supportable. And the idea it is local/cookie driven is even more unlikely, so the idea that it could be combated by clearing cache or using incognito strikes me as a little far-fetched – but I will of course change my opinion once there is evidence.
That doesn’t mean I don’t think airline pricing is wack. I do.
@MaelstromMonkey many people have had the unpleasant experience of booking a direct flight somewhere only to later discover that the airline changed their flights (aka cancelled the direct) and are sending them to their final destination with a plane change somewhere.
A “direct” flight has a stopover along the way.