These free online tools allow you to extract various information about files and Android internals. Some of the tools are focused on photo & video processing.

Online APK Analyzer

APK Analyzer can extract information from compiled binary resources and AndroidManifest.xml files inside of your app's APK file

APK Dump

Allows you to decompile Android app binary code into human readable dalvik bytecode

APK X509 Certificate Info

This tool complements the APK Analyzer by allowing you to dump X509 Certificate signature info (like issuer, subject, validity period,..)

Protobuf Compiler

You can use this tool to create language-specific sources from you're protobuf definition files, or even to dump content of encoded messages.

Android Partition Image Tool

Allows you to extract information from boot.img files, read-only mount sparse & raw ext4 image files, and browse and extract files inside of ext4 partitions

File Tool

Shows information and mime type of various binary files and because it is completely client-based, you can also use it to display information about very large files (several GB)

Hash Tool

Can create common types of hash (SHA1, SHA256, SHA512, MD5) from text and files. The files are not transferred to the server, so they can potentially be several gigabytes large.

Image Histogram Generator

Generates image histogram graphs from multiple images in batch and also allows to export histogram values into .csv file for analysis in your spreadsheet application

Pano Stitch & Crop

Automatically stitches multiple overlapping photos into one larger panorama image and also allows to crop the final image to the preferred size

Images to video

Experimental tool that can create time-lapse video from multiple input images and also mux in audio into the final video file

Open source licenses of libraries I used to create my tools

Sixo Apps

If you're curios about the technical aspects of Android or you like image & video processing apps, you might find something interesting amongst the apps that I've published on Google Play