Create very simple Mac App

I need a very simple Mac app that shows me the balance of a online shopping platform in the menubar of my mac and when I click on it a list of the recent 15 events (sales, product comments etc) is shown. Both values (balance and list of events) are accessible via an API. The data is automatically updated every 5 minutes and if a "sale" event happened a sound is played. The events are also listed in the notification panel. See screen designs for further info. Please use the word "sale" in your bid so I see that you've read the description before bidding.