I've been on this project for quite some time. The software I developed is a series of functions and some classes that creates interactive environment for a project using character LCD and buttons. You can have a menu to choose, enter numbers, choices, or texts. The template and a full demo source codes will be released together. Here is a teaser of the full demo:
I was demonstrating things like browsing through the menu, changing menu styles, entering numbers and choosing from lists, and entering text strings. I'm still working to identify the memory usage of the software but it shouldn't use a lot so leaving most FLASH and SRAM to the projects. Your project can good like in the demo. All you need is to write your project code and have the phi-menu take care of the interactions, when you need interactions.
I am asking for suggestions and comments. The phi-menu will work flawlessly with my phi-1 and phi-2 shields but should work for you if you're willing to make some changes. There are also many options of how many keys you need to operate the interaction, ranging from just needing one button for everything (thanks JO3RI) to all 6 buttons for max convenience. I can't demo that yet (need to compile and restart Lazy me)
Any comments is welcome!