Tincr is a chrome extension. You can simply checkout the source code and load it as an unpacked extension in Chrome. This will require that Chrome is in Developer Mode (go to chrome://extensions and tick the box). Alternatively, you can pack the extension yourself using Chrome.
NPAPI Chrome File API
Tincr relies on an NPAPI plugin (NPAPI Chrome File API) for all of it's native file support. For example, reading and writing local files from a chrome extension and watching local directories for changes. The source code for this is here.