Create a Mac app with Today extensions

I would like a freelancer to create an app for Mac OS X, that works on Yosemite, for a fixed price. The app should allow the user, via a GUI, to create a list of endpoints. Each endpoint should be an http/https URL to a JSON resource, a data type, and may contain optional HTTP authentication user/pass details. The user will also be able to specify the number of seconds between fetches (refresh time) for each endpoint. The app will save the login details to the OS X keychain and call the JSON resource at the interval defined by the user and cache the output until it is called again. The user will view a visualiation of the data in the \"Today\" view on their Mac. The visualisation will be one of the following: 1. A number 2. A number with the amount it has changed (both values provided by the JSON endpoint) 3. A line graph 4. Text They should be able to reorder the endpoints which will reorder the widgets in the Today view. The JSON will be in the format here: [login to view URL] And you can get an idea for roughly what the widgets should look like by looking at this iOS app: [login to view URL] There is no need for lots of work on the interface and although it would be good to think about App Store submission, at the moment, this is just for my own use. Because we might submit it at some point, any libraries that are used need to be properly licensed. The code should be clean and modular so that it is easy to add more visualisations if we need to later on.