The Basics
Here are the basic Tuxrocket Guidelines for making an app succeed. It comes down to this: act like you’re a company that a customer has purchased an app from. I don’t mean free support or anything. But provide a decent product with the kind of resources a normal human being needs.
Build a Website
Make yourself a nice website. Use a stock theme if you have to, but get a nice one. Ask for some opinions from ‘normal’ people. Plain HTML is fine. You don’t need a state of the art wiki, bugtracker, etc.
And get yourself your own domain name- host your project on SourceForge or elsewhere, but that is not a website. I’m talking top-level domain.
If you can do it, put a user forum on your site. Not for developers or hackers. For users. How to use the app. Feature requests. Help.
Create a Beautiful UI
Your app should be a pleasure to use- an experience so slick that users look forward to opening it every day.
Get a Nice App Icon
Get an app icon that sums up your app and also makes it a pleasure to see your app in a user’s deskbar.
Distribute Packages
Don’t force users to build and install source code. Along with the source download, use the openSUSE Build Service to create packages for the most popular Linux distributions. And work towards getting your package included in the official distributions or repositories.
Market to Users
You need to conduct electronic warfare. Every software company out there pays people, in some cases many people, to sit around coming up with ways to appeal to users. The reason they have to do this is because they have to convince people to hand over cash for their software. You, however, probably do not have that problem. You just have to interest them enough to try your app.