I don't have time to give an extensive and exhaustive answer here - I should blog about this. The same question comes up again and again. Here are some quick comments.

Analysis:

* Why is your app different?

* Is it a vitamin or pain-killer?

* What does it do? Not from your point of view, but from a customer's point of view.

Pitch:

* This will save you time ...

* This will let you do stuff you really want to do, but can't ...

* This will improve what you already do ...

Approach:

* Blog

* Get feedback

* Approach a few individuals and pique their curiosity

* Reduce friction.

I haven't been to look at your app, because you've made me do work to do so. There's no link I can click - why are you making me make that extra step?

So, what have you done?