RPN calculator with programmable keys and a code editor. Its programming language is based on Forth, but it comes with high level data structures like Maps, Lists, optional local variables and a built-in HTTP client what you can use to integrate to IOT hardware or control smart home appliances.

Features:
* User defined programs and configurable keys
* Tone generator, blinking camera LED
* HTTP client with JSON support
* Forth wizard / Stack juggling solver (https://youtu.be/n9aS3Iu6bf8)
* Unit conversions, finance functions like compound interest, discounting, tip calculation, IRR (internal rate of return), NPV (net present value), trigonometric functions, average and many more.

Language reference:
https://github.com/zeroflag/fcl/