ArduSTL - arduino handheld programmer

Recently I've made this setup (in the picture). It's arduino nano connected to OLED display and 5 buttons. Basically what it does is you can program this device without connecting it to computer. You can just select instructions (statements) that will be executed one after another. This statements are simple assembler like instructions. Language is based on STL or SL - statement list (it is used in Siemens PLC's).  It's my new idea so as of now code is in mess and there is no documentation. It's a work in progress.