We spoke to the SD Maid dev about the benefits of system cleaning tools

These 'boosting' or 'cleaning' apps are installed on hundreds of millions of Android devices, yet their benefits are disputed. Matthias Urhahn, an app developer who works under the pseudonym 'darken', spoke to me about such Android tools. Matthias – who asked that we use his first name – is the creator of cleaning app SD Maid and I called him to discuss his product and how it differs from other apps which go under the system cleaner banner.

On battery and performance boosting apps

I asked what Matthias thought of apps which claim to “boost your phone’s battery life by 20 percent" and suchlike. DU Battery Saver PRO, a popular paid app, claims it can help you to "get up to 70% more battery life for your Android phone". Similarly, Power Battery - Battery Saver, one of the fifty most downloaded free apps in the US, claims to improve it by as much as 60 percent.  

“Any type of app that advertises with a concrete number of boosting of battery life is a lot of bull**** in my opinion," said Matthias. "You can’t just say 'boost your battery life by 20 percent,' how would that work? It doesn’t.”

I asked if the same could be said for concrete performance improvement numbers.

“That doesn’t work either. You can’t give exact numbers for any type of improvement [...] there are thousands of different Android ROMS. [App developers] can’t just give an exact number,”  said Matthias, adding, “I would be very skeptical because those numbers are likely made up.”

I also asked Matthias for his opinion on the 'boosting' function of such apps, whereby it's claimed that you can tap a button to immediately speed up your device. Matthias said that, while he couldn’t comment on specific examples of this, if they worked the way he thinks they do, that it could work. For a time.

"Any type of app that advertises with a concrete number of boosting of battery life is a lot of bull**** in my opinion."

“It can [speed up the phone], temporarily, because exactly at the point when you killed all apps [...] and then start another app, that app could run faster,” Matthias said, adding, “it can look, to you as a user, that your device is suddenly running faster, but that’s just borrowed time, because the apps will all come back.”

I asked if Matthias thought it was worthwhile to use such apps with a RAM cleaning feature.

“I don’t think RAM cleaning brings any benefit,” he said. “Most people don’t understand how intelligent Android’s RAM management is.”

“My biggest gripe, actually, with those apps [is that they] pressure the user into [using them],” he told me. "If they would just say, 'we kill all apps for the moment', that would be a lot better.”

On SD Maid and what it does

So, how does SD Maid differ from other system cleaning tools? For starters, SD Maid doesn’t have a “one-tap boost” feature. Instead, SD Maid seems more concerned with the file-removal aspect of such apps. SDMaid’s CorpseFinder function can find and delete “leftover” files, from apps which have been uninstalled, while the SystemCleaner and AppCleaner features remove “expendable" files.

“These are files that won’t break anything if they are removed and, if they are actually necessary, they are recreated. They are generated files,” explained Matthias. In other words, it wouldn’t delete something that could not be recreated without user-input.

“I don’t think RAM cleaning brings any benefit,” said Matthias. “Most people don’t understand how intelligent Android’s RAM management is.”

Matthias used a music app which may save album covers as an example. These thumbnails could occupy hundreds of megabytes of space and may be left behind after the app is uninstalled. Matthias says this is sometimes simply the fault of the app developer: there are millions of apps and not all are built perfectly. Occasionally, however, developers leave data deliberately, in case you reinstall the app later, for example. This would mean the app returns with your previous settings or preferences.

To someone running out of space on their device, the opportunity to easily remove hundreds of megabytes of unused files could be very useful, but I feared that this app could result in a user accidentally deleting files they really wanted. 

"I am trying to make the app as safe as possible, but nothing’s ever 100 percent. You should look at the results before deleting,” said Matthias. 

I also asked if SD Maid could offer any battery or performance enhancement as suggested by other system tools. Matthias said any benefit in this regard would be a side-effect of using SD Maid and said he makes no promises for this. 

Final thoughts

It seems Matthias is taking a softer approach to selling the strengths of his app than competing system cleaning tools. 

“I don’t think SD Maid is an app that you need to religiously run to keep your device running well," Matthias told me. Instead, he said, it's more like "a file tool in your toolbox to use when necessary, like if you’re strapped for space.”  

SD Maid, then, is a fundamentally different tool from a supposed one-tap battery-improving, performance-boosting, CPU-cooling app. SD Maid chiefly aims to remove unnecessary files occupying space on the device, files which users may have trouble removing without such an app's assistance.

So, what advice did Matthias have for users who might look into adopting a system cleaning app?

"Don’t let the application tell you that your device is unsafe, running too slow or running too hot."

“Independent of SD Maid, people should [not] let themselves get pressured into anything by other applications. Don’t let the application tell you that your device is unsafe, running too slow or running too hot and that you should do 'this' now and everything will be great. That’s not good for you or your device.”

SD Maid can be downloaded for free in the Play Store and you can visit the github page for further information on its functionality. As for the apps that try to sell you on boosting and battery improvement numbers, where do you stand? Let us know in the comments.