A clever idea by Steve Streza: Ohai is a journal app that uses your App.net account to safely store photos and places you’ve checked in.

Ohai has a simple and delightful interface to flip through pages (days) of your journal with a timeline layout that makes it easy to add new places (with optional photos and personal comments). Ohai isn’t a full-featured diary app like Day One, but instead puts the focus on saving check-ins in a private journal that doesn’t force you to share where you’ve been.

Streza isn’t new to leveraging App.net’s service for building more than Twitter-like clients, and Ohai is another great example of the versatility of App.net’s APIs and file storage. Streza highlights one of the benefits of implementing the App.net API on his personal blog:

One other cool benefit of using App.net for the backend is that the data specification is publicly available. This means other developers could build apps that recognize your journal. So, if the developer of your favorite camera app adds support for Ohai journals, they could save those photos into your journal. Then, the next time you open Ohai, those photos are available. Other developers could build journaling apps for other platforms like Android, or even write competitive apps for iPhone. You as the user would not have to export your data and re-import it; it would just all appear when you logged in. It’s a wonderful deal for customers to have no lock-in at all, with open data standards for interoperability.

Ohai is $4.99 on the App Store.