The “throw it over the wall” approach is when you hire a firm to develop your app and hope for the best.
I once received a frantic call from a lawyer about a hot new restaurant delivery app being developed in a major city. They had gone through $120k of their initial $150k seed funding and the results were decidedly unprofessional looking. To make matters worse the development company told them that having Uberlike GPS functionality in their app was not possible. They had gone through a respected local web development company in the region and thought they were on solid ground.
Offshore Development Pitfalls:
Most likely the trusted local firm pocketed & spent $100k of their cash after outsourcing this project to an offshore firm they recruited on a popular freelance website.
The first issue is that you never get to talk to the actual programmers with these overseas firms. Instead you speak to a virtual receptionist with half-decent English skills who queries you about the size of your budget and your project requirements. Everything is possible at your budget accord to the person you are communicating with.
You make the first deposit for the project and the firm dives in creating the visuals and some limited online web functionality: which are the easiest parts of the project. The more technically challenging parts of the project are avoided and the waiting begins. After weeks or months have passed you are told that your budget has been used up and more money is needed. The truth is that this firm does not cover the areas of expertise required to realize your more complicated requirements and may be (if you are lucky in rare instances) seeking another outsourcer to handle these features if you are willing to foot another substantial fee. By this point the project has run out of steam and you have run out of money. Most visionaries give up by now.