Being truly anonymous on the Internet is practically impossible. A new app is hoping to make it a little bit simpler when you head over to your smartphone.

The Tor Browser, which is used around the world by people to sidestep trackers and surf the Web anonymously is now available as a free download to Android devices via the Google Play marketplace. It can be used in place of Chrome or any other browser you have running on your Android device.

Unlike those other browsers, which only offer a few privacy options, the Tor Browser is designed to anonymize you. It does that by never sharing your personal location or information with a website. Instead, it bounces your IP address around the world to make the site believe you're not you.

For some people around the world, this is a must-have. It helps you circumvent firewalls and filters, and allows you access to the free and open internet. For journalists, activists, and others--especially in countries with internet censorship policies--a browser like this could be a way to help them do their jobs.

There is, of course, another side to Tor Browser usage: It could always be used for illegal activities like buying drugs online, sharing illegal content, and more. That's why the U.S. Federal Bureau of Investigation has been allowed to hack into citizen computer systems without warrants, ever since a federal court decision in June of 2016. It's a way for law enforcement officials to track people using browsers like Tor for illegal purposes.

So, like anything else, Tor Browser can be used for good and for bad.

Here's another important note: It can only be used in certain circumstances. You see, the chances of Tor Browser ever coming to the iPhone are slim to none. The reason for that, according to the Tor Project, is Apple itself.

In a blog post on its website, the Tor Project said that Apple has specific regulations and "system peculiarities" that prevent the Tor Browser from ever coming to the iPhone. Chief among those problems: Apple doesn't allow other browsers to use anything other than the WebKit framework baked into iOS. That alone is a dealbreaker.

That appears to be that. If you're hoping to use the Tor Browser on mobile, it shouldn't be a problem for Android users. But on the iPhone, you're out of luck--and it'll likely stay that way.