For a similar project in a similar space (but with both a free android emulator, and the option for a dedicated hardware device), see [0]. I actually use it as

For a similar project in a similar space (but with both a free android emulator, and the option for a dedicated hardware device), see [0]. I actually use it as my preferred calculator on my phone. All the best, [0] https://www.numworks.com/ https://www.numworks.com/