An open-source iPhone styled web-app for Piwik.
Installation is fairly straight forward. You can copy it via FTP and access it via http://yourdomain.tld/path/to/folder. You will have to create at least one other user besides the admin user in your Piwik installation before you can use it. The easiest method is to create a user called view and give it view permissions to all your sites. Then copy the API key in.
Considering I'm forking this project I'd like to add at least saving the access token (for view access only!) due to the hinderance of having to enter it every single time you want to open it up.
Another possibility would be to compile a native application.