I have just found it and paid for it and at first glance it seems very very basic. It was only a couple of quid but 'myfitnesspal' is free and much more interesting to use.
A page to put in your surgeons details.
A page to put in your operation details, date, weight, bmi, hospital stay, intra operative complications? Unexpected findings and postoperative complications.
A page for surgical technique
A page for results from one month through to 6 years.
And that's it! Not worth 2.5quid really but maybe interesting to those having a bypass.