On Leetchi: If you've ever organised a gift for someone in the office, you know how tricky it is to get everyone to pay up. I can think of a very easy solution - don't force anyone to pay. Buy a gift to the value of the money that people volunteer to put in. If you work in an business of 30 people, and everyone has to chip in $5 every time there's a birthday, that's effectively garnishing everyone's wages to the tune…
And the problem isn't forcing everyone to pay, it's getting everyone who agreed to pay to follow up with it after the thing has actually been bought.
That said, I'm not sure we need an app either.