TL;DR
- Samsung has revealed the three most popular Good Lock modules.
- The company says Sound Assistant is the most downloaded app, followed by Theme Park and One Hand Operation Plus.
Samsung stands out from other Android phone manufacturers thanks to its Good Lock suite of modules. These apps allow you to customize your phone in various cool ways. Now, the Galaxy maker has revealed the top three most popular Good Lock apps.
Samsung detailed the most popular Good Lock apps in an official Newsroom post, based on cumulative downloads as of March 2025. It turns out Sound Assistant is the top Good Lock app, accruing 21 million downloads.
Sound Assistant is also one of my favorite Galaxy apps, allowing you to customize a variety of audio settings. Perhaps the most notable feature enabled by this app is per-app volume adjustments. That means you can adjust the volume of each app independently of the overall volume. This is useful if you like listening to music on your phone but don’t want to be blasted with audio from Reels and Stories while scrolling through Instagram, for example.
Sound Assistant also lets you customize the look and functionality of the volume slider/panel. You can even control exactly how much the volume changes based on a press of the volume rocker.
What else made the list?
According to Samsung, the second-most popular Good Lock app is Theme Park, which has accrued 17 million downloads. This app lets you create your own custom theme, starting with the wallpaper and overall colors/style.
The customization doesn’t end here. You can also customize the Samsung Keyboard, quick panel, volume panel, and icons in general. The company notes that Theme Park’s One UI 7 update also lets you tweak the shape and color of home screen folders.

Hadlee Simons / Android Authority
Finally, the third-most popular Good Lock app is One Hand Operation Plus. Samsung says this app had 16 million downloads as of March 2025. It takes the back gesture seen in Android and turbocharges its functionality.
You can perform the standard inward swipe from the edge of the display to go back, but you can also assign this gesture to another action. If that’s not enough, you can also perform diagonal inward gestures to activate additional actions. Some of the actions you can perform via these gestures include activating the recents menu, going home, controlling the volume, opening the notification shade, and more. Best of all, you can independently customize the actions for the left and right-hand sides of the screen. That means a standard inward swipe from the left can do something completely different compared to an inward swipe from the right.
One Hand Operation Plus also contains additional options, such as the ability to customize the exact angle of the gesture, the swipe distance required, the vibration intensity, and whether the S Pen is supported.
In any event, the one downside to the Good Lock apps is that they’re not available in all markets. So I hope Samsung makes a concerted effort to launch these apps around the world sooner rather than later. But I’d also like to see a few Good lock features come to One UI itself.