1- It will be a marvellous app/programme/website, if you can integrate Colwiz with Jabref (since Jabref is also written in Java) and/or Kbibtex. Extracting citations in Bibtex form will be much easier than now.
2- It is interesting not to see New Hart's (Oxford) style in a website/app prepared by researchers of Oxford University. It will be very kind of you if you can add it to the options.
3- Finally but momentous, it will be amazing if you can make google scholar to recognize -just and only- the articles shared to all world in Colwiz.