Sort out a windows app already developed

We require a skilled developer who has thorough knowledge of whatever programming skills are needed to issue out a problem with an app and is well experienced in open cart 1.5.6.4 and for future versions and All other aspects of opencart - no surprises at the end of the project that you did not know about this etc etc. Developer should be able to advise if there is anything lacking that we haven't mentioned. Need a developer to look and study an app built by a time waster (developer) This app had certain ability which has now stopped working - Someone needs to figure this out how to bring the functionality back. We need someone who is skilled and can figure how the app is built and what it does and how its working with opencart database rather asking the buyer all the questions. We need our issues fixed within 7 days. MAX budget £120 - it will not be negotiated afterwards - what you bid is what you pay. Please do no bid just for the sake of getting this project - If you haven't got the skills and in turn waste our time - you will be reported to customer services.