Tumblr founder David Karp thinks a lot about the web as it was 15 years ago. A web filled with blinking words, Shockwave Flash, and GeoCities pages packed to the brim with clip art. It was a weird, unstructured, seemingly limitless domain where, armed with a few HTML tips from a friend or message board, you could build your first home page and publish it to the world.

But then everything changed.

“In the early 2000s, [the web] started to take a pretty sharp turn towards vanilla, white profile pages,” says Karp. To him, Facebook’s stark white pages weren’t refreshing like they were to MySpace refugees — they were restrictive. “The draw to the internet for me was this idea that it was a space where you could really create an expression of yourself — an identity that you’re really, truly proud of.” Karp saw sites like LiveJournal, Blogger, and GeoCities disappearing by the day. “Social networking” sites, where every username was printed in the exact same font, were winning out.

Fast-forward to today, and Karp has turned accidentally hypocritical. Inside Tumblr’s mobile app, 180 million blogs are all colored the exact same shade of blue, with hardly any distinction between them. Tumblr was always about more than the content filling up your blog — it was about creating a digital room of your own, decked out with posters of all your favorite things. Tumblr became famous for making blogs on the web customizable, and now it’s finally catching up to a world gone mobile. It’s launching its new mobile app for iOS and Android, which bundles in a variety of new editing tools to customize your blog on your smartphone for the first time.

Tumblr’s new tools aren’t revolutionary, but in a world filled with social networking sites that increasingly force their users into tiny white boxes, they recall a charming, messier age when it was easy to express yourself online using any mode you chose. It’s an age worth revisiting, I think; interfaces didn’t always make sense but somehow felt more personal. My DeadAIM messaging app, for example, was wallpapered with an image of Morpheus from The Matrix, but I wouldn’t have it any other way. My friends hated my orange Comic Sans IM font, but I wasn’t going to change. These days I’ve come to assume that cleaner, more minimal designs are better, but Karp hopes to convince me otherwise.