The only junk on your phone is your "junk cleaner" app, and here's the proof

As it currently stands, Google Play is the largest mobile storefront in the world, being host to more than 2.2 million apps, just slightly more than what Apple’s App Store offers. Yet you don't see Google gloating about it much these days, despite the two companies' endless rivalry – but why? Here's a theory: in reality, that number is not a win but a disaster, and the big G knows it. And the reason for that is simple – those two million apps? Most of them are garbage.

It really is remarkable just how awful the depths of the Play Store can get and just how little policing actually occurs during Google’s app vetting process. Just search for any semi-popular app and scroll down – there, you'll find all the knockoffs with a suspiciously similar name, the copious amount of “guides” for the app, the so-called extensions which do pretty much nothing useful, and so on. Each one of these had to be approved to get to the storefront, and apparently did so without a hitch. And let’s not even start with all the malware incidents during the platform's relatively short life. What we want to discuss here, though, is something else entirely - while all of the above are real problems, most of the time they're not famous enough to warrant discussion.

However, there exists a specific type of app that somehow manages to be extremely popular despite being blatantly deceitful to its users - the so-called "cleaners", "boosters", and/or "antiviruses". Looking at a list of popular apps reveals that these so-called utilities consistently get high install rates and glowing reviews, which to us is very suspicious. So we decided to do a little investigating into what these apps actually do and why they're so popular.

Mind you, the tests we performed were far from scientific, but even then, every one of the apps we chose was obviously designed specifically to take advantage of its users, while providing no useful functionality in return. Unless you count riddling your phone with adware as useful, of course – there was plenty of that.

The existence of such scam apps is not surprising in the least – for as long as the Internet has been around, there’s been plenty of people willing to take advantage of users’ lack of technical prowess. Remember BonziBuddy? It was a piece of software, most famously in the form of a purple monkey, which was supposed to help users navigate the Web. Also, it was a nasty piece of adware, littering its users’ desktops with unwanted advertisements. The case here is almost the same, except the monkey is, thankfully, nowhere in sight – these apps advertise themselves as a real, useful utility, but in reality serve mostly as a vehicle for serving a ton of ads.

So it seems logical Google would want to get rid of such scam apps, wouldn’t it? Yes, and that’s precisely… wait, what?

How naïve of us to think a billion-dollar corporation would actually care for its users - no, the reality is that these apps rake in a ton of cash, and Google, their biggest ad provider, gets a significant cut of it. So it’s only natural for the company to want to promote them, nevermind affected consumers.

And here’s the saddest part – users love it. Just a glance at the reviews shows thousands upon thousands of misguided recommendations, with only the occasional 1-star reviewer seeing through the lies (though undoubtedly a large number of the positive reviews are fake). A particularly curious case, for example, is the one where a user was warned by their carrier about a certain junk cleaner actually being adware, which prompted them to leave a negative review on the store page. An extremely vague reply by the developer, however, was apparently enough to reverse the user’s opinion, who then proceeds to actually thank the devs. And this is just a single example - such apps are commonly advertised with misleading ads designed to scare the user into thinking they're at risk, prompting them to install a needless piece of software.

But it isn’t just Google’s fault, really – for this whole genre of scam apps to be as successful, there must be people willing to use them. And this is precisely where decades of marketing come into play – it wasn’t so long ago when a computer without some sort of antivirus installed was considered pretty much unusable online. This paranoid line of thinking – that one is always threatened online, that there’s always something wrong with their machine – seems to have stuck through the years, and now is precisely what scammers are banking on.


We analyzed five of the most popular “cleaner” apps on the Play Store, chosen from the daily list of most downloaded apps, as provided by AppAnnie. Each app was installed on a freshly reset Blu Vivo XL running Android 5.1 Lollipop. All traffic on the device was captured using Fiddler, a free network analysis tool. We spent a few minutes with each app, trying out most of its advertised features, save for those which required creating a user account or installing a separate app. 

Clean Master

The most popular app of this kind on the Play Store, Clean Master is made by the infamous Chinese developer Cheetah Mobile. Advertised features of the app include: junk file cleaning, phone boosting, antivirus, CPU cooling, and more! Actual features, however, are mostly the following: ads inside the app; ads on a second lock screen, which Clean Master labels “Charge Master” for whatever reason; ads injected into webpages when using the “safe browsing” feature; and also the constant downloading of even more ads, including videos, most of which we never actually encountered during our time with the app. Massive points for effort, however – the app almost has a few cool features, and can actually be described as somewhat pretty, though both points are quickly diminished by all the lies about "cleaning junk" and "CPU cooling". In our test, one of the first things the app did was to access several very questionable domains, including ones linked to porn and gambling sites.


It turns out math is a much more malleable concept than we previously thought, and it’s the folks at PSafe we have to thank for the realization – somehow DFNDR managed to give us “700MB speed-up memory”, despite free RAM staying at almost the same amount before and after the app’s usage. The same thing happened with its junk data removal tool, which did absolutely nothing. For what it’s worth, however, its “antivirus” did send some data to a web scanning service, but most of the time the scan consisted of downloading ads. A user review on the Play Store described the pop-up ads as “predictable”, which is nice! - it’s good knowing exactly when you’re going to be taken advantage of, in return for a mostly nonfunctional service.

Junk Cleaner

One of the two apps with the same name on the list, Junk Cleaner apparently aims to be as unobstructive as possible, immediately removing itself from the app list and becoming accessible exclusively through a persistent notification (convenient!) A feature sorely missed, however, is the decimal comma, a.k.a. the difference between 434 MB and 4.34 MB of deleted data – though this is surely just an oversight to be fixed in a future update. We can’t give it enough praise, so we’ll let its store page description do the talking: “Most of Android users suffered from the phone lagging and insufficient memory when they using their phone, if you are looking for a cleaner for your phone, Junk Cleaner will be your best choice. Free to try it now!”

SUPO Security

An app so secure, it becomes inaccessible after just one use – truly revolutionary. We actually had to install it twice, as the first time it somehow blocked access to the Play Store, while also deleting almost all traces of itself. What was left, though, were tha app's background services, which pinged the servers of QQ, a popular Chinese chat service, once every two seconds. Many users also report being bombarded with apps after installing the app, though we did not share that experience. A fun quirk of the app is just how hard it is to remove, since it asks for permissions which can effectively disable uninstalling the app, unless one knows exactly where to look.

Junk Cleaner / Junk Cleaner Lite

In the words of the developer: “Junk cleaner, professional optimize your phone performance. Make your device running like new again.” We actually started with the Lite version of the app, but quickly found ourselves wanting more functionality, of which we got plenty – though most of it consisted of, you guessed it, ads. Just like Clean Master, here we got a few problematic ad sources, including one previously linked to the distribution of Android malware, along with a ton of pop-ups, and a lock screen overlay (filled with ads, obviously). Interestingly enough, this app actually reported less RAM usage than there really was, which seems counterproductive in an app designed to lie about cleaning memory.


Unfortunately for everyone, the popularity of scam apps just like the ones we looked at is only growing bigger, in large part thanks to Google, which actively promotes them to Play Store users, along with the many device vendors who preinstall them on their phones. Even though we only tested five of the so-called "cleaner" apps, we encountered many, many more of them further down the popular apps list. When even the most widely used ones are, as we found out, complete scams, they quickly become indicative of the overall climate in this particular app niche, so while we cannot discount the existence of actual applications performing such services as advertised, we still recommend you avoid using them like the plague.



1. bohdan4ik13 unregistered

I use CCleaner for clearing cache and nothing more

15. buccob

Posts: 2975; Member since: Jun 19, 2012

Android already has Cache cleaner inside its settings... (at least Xperia version has it)... You have to go to Settings - Storage - Internal Memory - Cache data... tap it and it will clear it.

22. matistight

Posts: 997; Member since: May 13, 2009

So ccleaner profits off you for doing something your phone mostly has built in. Clearing your apps in the app manager is all those apps do.

26. aklipii

Posts: 12; Member since: Dec 29, 2010

They don't profit since the app is free and it's not displaying ads. And unlike the system cache cleaner, which cleans your SYSTEM'S cache, ccleaner does that for every app individually.

32. sgtdisturbed47

Posts: 969; Member since: Feb 02, 2012

Nothing in today's world is free. They're making money somehow.

47. ibend

Posts: 6747; Member since: Sep 30, 2014

yeah.. like selling users information or something..

39. marorun

Posts: 5029; Member since: Mar 30, 2015

As if only google play store is full of trash. 3 time now apple cleaned its app store and its still full of similary crappy apps. Google now also making a new policy thats will also inform better client of such potential issue with app like information stealing ect. Iphone arena at its best.

2. Plasticsh1t

Posts: 3109; Member since: Sep 01, 2014

What about HTC's boost+? For me it closes apps in the background and saves battery.

10. TBomb

Posts: 1568; Member since: Dec 28, 2012

I have the same question....

12. Chris.P

Posts: 567; Member since: Jun 27, 2013

It's freaking useless, just like all of them. Memory on mobile phones doesn't work like on Windows. When you're maxed out on memory, the least used app is killed off. Worse yet, killing off background apps is actually a net drain, not gain, on battery. That's because each time you next open the app it needs to initialize and load all of its crap, sucking up more CPU cycles, and therefore, more battery. That's not even mentioning the fact that even though you may have the app closed, it can still run its own background processes regardless. It's a crap idea, has been crap in the past, and is even more crap today with intelligent built-in memory management in modern Android builds. There's only one reason manufacturers include third-party crapware like this: sponsored deals. And there's only one reason crapware makers pay for it: ad revenue.

16. Chris.P

Posts: 567; Member since: Jun 27, 2013

I can't quite remember, nor check since I'm out of the cycle, but I'm feeling rather certain that Boost+ was CCleaner hidden under signature HTC UI design. I could be wrong.

17. BGChicago

Posts: 225; Member since: Nov 16, 2014

Not on "Mobile" but on Android. The beautiful and smart BB10 OS doesn't work like that. You can deny or allow background process to apps. Also, most Windows apps now a days have their own background process and services . It's been like that for a while actually.

54. 10033859

Posts: 31; Member since: Jun 29, 2016

You can do the same and manage other permissions on Cyanogenmod, Res. Remix and a few others, as well as touchwiz android M

3. ibend

Posts: 6747; Member since: Sep 30, 2014

those apps is useful for cleaning cache.. but it's better to stick at cleaner that come with your phone's UI.. and apps on junk list above is just as useless as battery safer, memory cleaner, or even antivirus apps on android

7. joeytaylor

Posts: 957; Member since: Feb 28, 2015

Can't you just clean your cache yourself

4. sissy246

Posts: 7124; Member since: Mar 04, 2015

"vehicle for serving a ton of ads" Mean like you PA

6. medtxa

Posts: 1655; Member since: Jun 02, 2014

well that's what website that live from ads do. complaining about it is just stupid.

11. sissy246

Posts: 7124; Member since: Mar 04, 2015

The same with apps, so why is it OK for PA but yet PA thinks it's wrong for apps.

13. Chris.P

Posts: 567; Member since: Jun 27, 2013

Are you kidding? When you visit PA, you're essentially agreeing to ads (which you probably block) in exchange for information and editorial content. You DO actually get that, this article being case in point. When you install crapware like all them cleaners, you're agreeing to ads in exchange for the advertised utility. You DON'T actually get that utility, this article being case in point, but still get served ads. Notice the difference?

18. sissy246

Posts: 7124; Member since: Mar 04, 2015

They are both just as guilty. JMO, you have yours. Just like the old saying , opinions are like azz holes, we all have one. If all are opinions were the same this site would be pretty boring. LOL

20. Wiencon

Posts: 2278; Member since: Aug 06, 2014

You just won the award for the stupidest comment this month Great article, I'm happy someone finally wrote about it, I can't help but laugh at people that use those apps, it's kinda sad really

37. sissy246

Posts: 7124; Member since: Mar 04, 2015

Well is it not true And it is a good article , you are right. I don't use that crap either.

41. marorun

Posts: 5029; Member since: Mar 30, 2015

All the example given are crap. But there is very good one. like Bitdefender.

33. southernzombie

Posts: 357; Member since: Jan 17, 2017

I think you are slightly missing the point of this article. This article is really about the fact that the apps are full of ads. The problem with the apps is that all they are is basically adware and don't actually do what they are downloaded for. Ads on a website along with the content you actually came for is to be expected. That's why you don't have to pay to post your opinions on PA.

38. sissy246

Posts: 7124; Member since: Mar 04, 2015

I understand and that is why I don't use that crap either. I don't use them because they do lie about what they do. I am just saying they both make money on the adds. I know it's for two different reasons.

40. marorun

Posts: 5029; Member since: Mar 30, 2015

So apps cannot live with ads only website? lol

5. sissy246

Posts: 7124; Member since: Mar 04, 2015

I clean stuff off my phone my self.

8. SupermanayrB

Posts: 1188; Member since: Mar 20, 2012

Stopped using apps like these & stopped advising customers of such in 2010. I just plug my phone up to my PC, multi-select the creak that's not needed (usually cache from games) & I'm good.

9. AmashAziz

Posts: 2934; Member since: Jun 30, 2014

I hope the junk cleaner that comes with the phone by the manufacturer itself, is useful to some extent. On iPhone though, there's just one junk cleaner app hidden inside an app called "Battery doctor". And it does wonders to clean storage. For example, on an iPhone 5s with 136 MB of storage, running the app once cleaned about a GB of junk and made about 1.1 GB of storage available. Find batter doctor in the app store.

21. Wiencon

Posts: 2278; Member since: Aug 06, 2014

I'm pretty sure most of that crap was made by the app itself Anyway, I don't believe you, iOS apps are sandboxed and they can't remove any files other than those "owned" by the app itself You have to get jailbreak for those things

* Some comments have been hidden, because they don't meet the discussions rules.

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