Great idea though. (I might use it soon.)
The screen shot is less important than the description and the discussion. A thumbnail will suffice.
Seriously, I think Tappr and several others are just using this to advertise.
One slightly negative impression: while there are already lots of good submissions and it looks like people are using the heart button, there are very few feedback comments so far. I particularly like the idea of a smaller, more tight-knit group of HNers giving each other feedback, since it seems nearly impossible these days to get any attention for a Show HN post without preexisting internet fame or a voting ring, so I found it a bit unfortunate that Breakpoint seems be starting out more in the direction of show-off gallery than a place for substantive discussion and critique in the HN vein. I'm not really sure how to remedy this. Perhaps placing more emphasis on discussion vs. screenshots could help?
This is one of the reasons behind my Google+ community for and about Internet Startups  - currently the largest one about this topic - where you can post under the "Introduce your startup" category and get precious feedback.
Although it looks like one of the screenshots I added is not displaying. Could just be hackernews traffic maybe, I noticed there is also an image error with the ad in the sidebar.
 Looks like both screenshots are showing now.
Edit: The developer (thanks Drew!) emailed me within ten minutes of posting this, figured out what the issue was, and pushed a fix. I'm impressed.
Here's my weekend project dbinbox: https://breakpoint.io/144-dbinbox-makes-it-easier-for-people...
Given that most Show HN's never hit the front page (mine was in the 1st page of the 'new' tab for just 20 minutes!), hopefully this fills in a niche that seems to be missing from HN. Good work!
The main difference is that we're a platform for sharing ideas, and you're sharing projects that already exist. In any case, good luck with this!
As others have said, the screenshots management bit needs to be improvement - it's a bit of a guess as to what'll work best right now. But I imagine that will come with time.
 = http://news.ycombinator.com/item?id=5030945
EDIT: Yeah, the site is getting hammered right now.
Frankly, submitting "Show HN" posts here is now useless and a bit frustrating. Most of them seem to get lost.
- Use Gravatar for the avatar
- Add a field in the profile for GitHub
Also, just added mine... http://breakpoint.io/116-straply/