Hello,
During development of one of my project I created this simple library: SimpleTaskManager git.
This is my first library. I'll be adding more examples.
I hope it will be of use to somebody 
Simple Task Manager is a simple framework for creating task based code. The goal is to never use delay() so many tasks can run "concurrently" and to be able to neatly segregate your code features. It is designed to run on devices with limited memory like Arduino Uno. It loosely bases operation workflow on RTOS (Real Time Operating System) in that you can time tasks in semi predictable intervals.