I used Blockspring back in college when it first came out for a bunch of random projects and more recently for lead lists. In the past couple months I actually hopped on a call with one of the co-founders to provide some feedback on the product. For a while it didn't seem like they were updating anything, but in the past year to 6 months they really improved a lot of the features. Pretty cool to see it work out for them, congrats!
