Ask HN: Use app first, register later

Hi. My webapp is a good example. It's http://www.SignAppNow.com - a simple and easy way to create sign up sheet. You can immediately use it without registering and there is no limit to the number of sign up sheets you can create. If you want features like editing your sign up sheets, custom url, and so on, that's the time you can register. Thanks!

http://pluspanda.com

Just click on the big green button. A real account is created. If you don't claim it, it gets deleted. Pretty simple, and nearly everyone who is vaguely interested always clicks on the green button...

I'm not sure if this meets your criterion, but StackOverflow does not require registration but it is more beneficial to do so: http://www.stackoverflow.com

My startup Feedity allows that - http://feedity.com

Try first, register later to save your work.