Cleanup app for conference room scheduling

I need existing code for an android tablet app cleaned up. A Freelancer built the app but was unable to resolve some of the bugs identified in testing. A general overview of the initial requirements is as follows: I need an app built for a tablet that will be mounted outside of my conference room. It should read the office 365 calendar for that room and display if the room is free or occupied. It should also show the upcoming bookings for the day. All meetings displayed should show the meeting subject and organizer based on the details of the office 365 calendar. Using the tablet touch it should allow a user to “quick book” the room if it’s free from the tablet for several predefined increments. It should also allow the user to cancel, extend or end early existing meetings. When a booking is nearing the end, there should be an audible alert at predefined times prior to the end of the meeting. Deliverables will include the ability to install to a tablet as well as the source code. I can provide the existing code as well as a list of the bugs identified that need to be resolved. This was a fairly small project to begin with but the other freelancer was not able to resolve these bugs without “breaking” something else. We hope you can salvage much of the code without having to start over. Please note, in an effort to be efficient for both of us, we will only be able to have 1-2 rounds of testing this product. We are happy to answer any questions along the way. Communication will be a top consideration as we cannot keep testing versions just to identify new issues created while trying to fix the bugs as that’s why we stopped the last project. You will need to setup an office 365 business account to work on this. They have free trials available but we will not be able to provide a login to our live accounts. Milestones: 50% upon successful working app we can test and 50% upon delivery of source code. Deliverables: Android installable app, source code.