Which app should I make this year?

So I'm going to make an app this year...

Here is the list of potential apps I came up with so far. Will you help me select the one I should make? Which app would be the most useful one?


theGathering
A web site and corresponding app with simple tools to use during a face to face or virtual ‘gathering’. For example: a timer, a poll, your mood, jingles, virtual flipcharts, actions etc. At the end of the gathering, you get a summary email.

Micro360

An app to get 360 degree feedback on how you are doing on a particular skill. Just one skill. 

Something with Checklists

An app to help  you create and use your own dynamic job aids. The job aids will visually adapt to how you are using them.

Like It Is

An app to get instant feedback on how you are doing. The next time you are doing it, you'll get a reminder of the suggestions people gave.

So You Think You Can Learn

A wizard-like app that helps you understand what it will take to learn something.

The Big Dare

A global daily or weekly Truth Or Dare to make the world just a little better.

Dandelion

An app to keep track of how ideas and concepts spread.

or .... ?

Which one do you think I should make?