I'm curious to hear opinions on this issue: I've been thinking about an idea for a Mac app (possibly iPhone app as well) that I want to develop. After doing some research online, I found a website describing an in-progress web app that is very similar to my idea. With little signs of recent progress, I even contacted the developer, who replied that he was almost finished with the project, but was currently making slow progress due to another job. I want to continue with development of my Mac app but feel like I might be encroaching on "his idea," even though it is not completely unique. Thoughts? Do I have any obligation to stop my own development plans?