For solo entrepreneurs like myself, one thing like setting up and managing my own mail server isn't a big deal by itself, but add that to all the other little things I do myself (not to mention the other stuff that Google Apps makes easy) and it's an easy choice to simply set up Google Apps and forget it.
The chances of Google stealing my idea is virtually nil, and if they wanted to steal it, they just have to go to my public website. Trying to hide what you're doing just seems silly to me in this day and age, so I'm just super-open about it; I'll blog, tweet, & FB what I'm doing on my start-up any time, and let the chips fall where they may...
Yes, obviously I'm a bad designer. I'm surprised that you say it's unclear what the function of the web app is. It's described right at the top. Also, it's funny you say to put the screenshots on the home page. I had it like that for over a month, but everyone said to put them on other pages... :)
Here goes:
1) It connects to your Twitter & Facebook (oAuth)
2) You make a list of keywords you want to follow (up to 20)
3) Refynr looks at those you are Following on Twitter, and only shows matching tweets in your Refynr Stream
4) Refynr does the same with your FB News Feed and shows those posts in your Refynr Stream
5) Refynr saves all those "refyned" items in it's own database so that you can view them at your leisure (overcoming the limited time that Twitter saves tweets for search, etc)
6) Optionally, Refynr can send you a Daily email of your most recent items in the Refynr Stream
But any other feedback for the questions I posed?