I'm working in a set of utilities for self-organization called orgutils.
It already has an event manager (calendar) and a task manager (todo).
The goal is for those programs to be scriptable. They are non-interactive filters that do not do colored output or other forms of pretty-printing, so their output can be used by other utilities, in a shell pipeline for example.

I am now writing habit, a habit tracking software that will print a report of how the habits are being realized during the user's routine.
I'm thinking in add some kind of gamification to that. The user gains experience when doing good habits and levels up when gaining enough experience.
I am looking for a relation between experience and level, like a mathematical function that makes leveling easier in lower levels and harder in greater levels. I'm also looking for a rate for experience gaining.
I'm thinking in using a logarithmic function for the experience-to-level mapping and make experience being gained at a constant rate every time a good habit is done.

However, after I present this gamification idea to someone, they replied me with:

Quote:do you take into consideration that gamification might cause addiction-like (self-)gratification issues for the user

The main purpose of leveling in a gamificated system is to get some kind of reward when leveling up. However, I don't think a simple CLI utility will cause such kind of addiction.

In any case, other CLI utilities I'm planning for orgutils are:

• schedule: A utility that convert tasks into events, that is, you describe your tasks and how much effort (in time) it takes and then it will schedule the tasks through the calendar.
  
• clock: A utility for clocking time usage and the time spent on activities. I have to check how people do that on orgmode and mimic their workflow.
  
• people: A contact manager that works with mutt(1).
  

I'm also reading orgmode's manual to get ideas to copy.
Orgmode's agenda view is implemented by agenda(1), a shell script that is included with orgutils.