How much Equity should I get?

Well some think its a duplicate to another question but i think its different cuz all four of us in the team are not the coders, developers or programmers & also my question is different cuz the other 3 are investing their money.. im not.. So this makes it tricky..

Here are some of the Details about the project first:

We are 4 guys working on an App. The app is still in Coding Process. I'm the last one to join the team. The Team worked for 2 months before i joined in. I was told that i will be taking care of marketing & promoting the app. But since I have joined, I have been attending all the weekly team meetings, discussing about the layout, design, testing the IPAs. I was giving my time, energy and inputs to the actual developers. I also also voting when there is a debate and my vote is counted.

The whole budget of the app is about US 25,000$.

Investment:

1st guy - 17,000.
Contribution towards the app is very little to none as he is the main investor.

2nd guy - 5,000
Contribution towards the app is good.

3rd guy - 3,000
Contribution towards the app is good.

My Investment - None.

All four of us are not the developers. We all do only the layouts and make the SRSs and send them to the main developers in Asia. I joined the team about 6 months back and the app should be out in the next 6 months from now.

My responsibilities have changed and now are to come up with new ideas to make the whole app experience better, discuss and check the progress with the developers and once the app finishes, the whole marketing will be taken care by me.

This will be making press releases,. submitting app to online forums, app reviewers, work on the videos and more.

The time that i spend on this app is roughly 3 hours/day (everyday for the past 6 months) and once the app finishes I will be working about 5 hours/day.

I have been doing all this for free with no compensation. How much equity should i expect and settle on? The equity I receive - will it be diluted once the VCs join in? What clause should I include in the agreement that stops the equity from diluting and is there any class stocks (a or b, super voting stocks) I should ask for?

Thanks for your comments & answers..