This free online tool allows to convert PNG files into ETC1 texture files and back. You can also convert multiple files in batch at once.

Note: This tool is completely client-based and all processing is done on your device. That means your files are not transferred to the server.

If you you're an Android enthusiast that likes to learn more about Android internals, I highly recommend to check out the Bugjaeger app. It allows you to connect 2 Android devices through USB OTG and perform many of the tasks that are normally only accessible from a developer machine via ADB directly from Android phone/tablet.

Ericson Texture Compression (ETC)

This tool can create compressed ETC1 scheme textures from PNG files and also convert the output .PKM files (compressed with ETC1) back to PNG files.

ETC1 compressed textures can be used by OpenGL ES and are supported by most Android devices.

You Want Other Features or Something Is Not Working

In case something wasn't working, or you would like to have some other features, write directly to my email -
roman@sisik.eu.

I'll try to fix bugs and add requested features if possible.

Other Useful Tools

If you want to get detailed information about Android's APK files, check out my APK Analyzer tool.

Additionally, if you you're an Android enthusiast that likes to learn more about Android internals, I highly recommend to check out the Bugjaeger app. It allows you to connect 2 Android devices through USB OTG and perform many of the tasks that are normally only accessible from a developer machine via ADB directly from Android phone/tablet.