Android App for Internet-Controlled 3D Printer

I need an Android app that allows controlling my self-built 3D printer over the internet. The app should have a live video stream feature, enable G-code file transfer, and provide remote control capabilities.

The details of the project are as follows:
- The 3D printer currently uses Marlin 2.0, but I am open to switching to Klipper or any other firmware that you find easier to integrate.
- My printer setup includes a Raspberry Pi 5 as the host, a BTT Octopus Pro as the microcontroller connected to the Pi, and a 15-inch touchscreen display.
- The 3D printer has three extruders, and I require a mixing feature for these, similar to what Marlin provides.
- The Android app should allow for controlling the machine through the internet and a 20-inch touchscreen display. This includes starting/stopping printing, adjusting printer settings, and monitoring printer status, as well as everything that Mainsail offers.
- The live video stream should be 720p quality.

Ideal skills for this job include:
- Expertise in Android app development
- Familiarity with 3D printer firmware (Marlin, Klipper)
- Experience with integrating live video stream into apps
- Knowledge of G-code and 3D printing process
- Understanding of microcontroller systems and Raspberry Pi integrations

Please note that full details of the microcontroller and drivers will be provided.