Exploring Android apps for fun and profit

Jonathan Cooper
2 min readAug 7, 2020

Smartphones have become an extension of our bodies. We use mobile apps for everything from sending money to shooting movies, but for the most part, apps are black boxes. On Android, apps can request information about installed apps and their components from the PackageManager. You can see what an Android app is made of using APK Explorer.

Discover Hidden Apps

Every Android version comes with Easter Eggs, hidden apps that are interesting to some enthusiasts. APK Explorer makes finding Easter Eggs easy, by displaying them in the list of apps instead of having to search through random tap combinations in the Android UI.

Opening the hidden Android Easter Egg app that came with my Galaxy S8.

Learn How Apps Work

APK Explorer can help you learn about other apps’ architectures. It’s often useful to see how other developers use Android components to build features. APK Explorer can help focus code reviews by highlighting public app components.

Public components the Wireguard app uses to route all device traffic through a Wireguard VPN tunnel.

Find Bugs

Sometimes, developers accidentally mark the wrong components as public. APK Explorer lets you open public Activities and view public components in apps that may not have been intended to be opened directly by other apps.

An exposed Activity in the call app on my Galaxy S8. It seems the developers did not intend for this Activity to be called with an empty intent.

Source Code

Get APK Explorer on GitHub. The app has no ads and doesn’t even require internet access.



Jonathan Cooper

I’m a cybersecurity consultant who develops software. I help agile teams deliver secure digital experiences to their customers.