Your Audience Is Human
Why do many new projects try to sound like established businesses? Why not be honest and just say:
Hi there, if you’re here it’s probably because you’re a friend or family member of mine! Thanks for trying out my web-app. I’d love to talk to you about your experience using it - just call me anytime (you probably already know my number).
I’m a big believer in being real, and writing your website as if you’re having a conversation with a real human being who you might actually talk to about your project. Over time, as it grows, your tone will naturally change if you follow this formula, because you’ve got different things to talk about with different people.
But most websites and new projects just copy the tone of the most popular websites they see, out of some unconscious belief that the way they present themselves now had something to do with their early success. It’s a common mistake - cargo cult, or imitating the external form of a success without understanding why it a success or the true internal mechanics.

An example of some really great honest copy is from a charity called GiveWell’s website. I was shocked to discover they have a section in their main navigation called “Mistakes”. Amazing! Here’s a selection from that page:
Ongoing: tone issues
How we fell short: we continue to struggle with an appropriate tone on our blog, one that neither understates nor overstates our confidence in our views (particularly when it comes to charities that we do not recommend). A recent example of a problematic tone is our December 2009 blog post, Celebrated Charities that we Don’t Recommend. Although it is literally true that we don’t recommend any of the charities listed in that post, and although we stand by the content of each individual blog post linked, the summaries make it sound as though we are confident that these charities are not doing good work; in fact, it would be more accurate to say that the information we would need to be confident isn’t available, and we therefore recommend that donors give elsewhere unless they have information we don’t.
We wish to be explicit that we are forming best guesses based on limited information, and always open to changing our minds, but readers often misunderstand us and believe we have formed confident (and, in particular, negative) judgments. This leads to unnecessary hostility from, and unnecessary public relations problems for, the groups we discuss.
I know a lot of people who are perfectly willing to talk about our weaknesses with friends and family. Why is it amazing that this conversation would happen on a website? I think there’s a really low bar here, and it’s a big opportunity to make your project stand out if you just use your website not as some digital brochure full of marketing-speak, but as an opportunity to start a conversation with the real people reading it, respecting their intelligence, just as you would offline.
Being real makes you stand out.