As a freelance software engineer, I've worked on all kinds of projects from all kinds of clients. One thing that's been clear time and again is that the success of a project often hinges on planning and management. No amount of development experience or engineering expertise can salvage a project that is doomed due to mis-management. Want to know how to manage your next big project? Here are the keys to failure:
Have wildly unrealistic expectations.
Your app is guaranteed to make millions. The key to success is simply to copy an existing popular app and change a few details slightly. The world is just waiting for the next Candy Crush or Clash of Clans clone! Furthermore, you can absolutely hire a single developer to build your hit AAA-grade cross-platform multiplayer game in two months for $1000. The only reason it costs big studios hundreds of thousands (or millions) of dollars to build a similar game is because they don't know how to spend their money wisely! There is no need to refine your concept down to something less complex and more indie-budget friendly.
Once you finish the app, don't bother advertising - it will spread quickly from word-of-mouth and you'll have hundreds of thousands of users in no-time flat. Simply publishing an app is a guaranteed path to success!
Throw planning out the window
Project management? Who needs it? Why waste time learning how to use a simple task-management system like Trello or Google Sheets, when you can just send emails? Losing track of who is doing what, and which tasks have been completed, is all part of the seat-of-your-pants fun of managing your big project!
No brakes on the scope train
Project planners at big studios are much too conservative with scope. Why place limitations on the number or complexity of features in your app? Every new idea that pops into your head should be added to the to-do list (but remember never to keep an actual to-do list, because that would be too easy to reference). Your developers might tell you that the project will never get finished if you keep this up, but that's just because they're lazy and don't want to work hard! What do they know about how long it will take them to complete a task?
Your average mobile game might launch with a limited but solid set of core features and then add lots of new features in subsequent updates if the game is successful, but you know better. The key to success isn't crafting a solid foundation and then looking for a customer base to provide you with security and revenue to build upon that foundation. The key to success is to build a staggeringly massive app with a feature list so long it would put Leo Tolstoy to shame, and then see if anyone wants to use it!
QA is for suckers
Studios love to waste money, so they set up a Quality Assurance team to burn money under the guise of "investigating and cataloging bugs". You don't really need that though; you can just spend 15 minutes or so testing every other new build from your developer, and let him know if you spot any bugs. You don't have to be too specific; after all, it's not like he has anything else on his plate than trying to figure out exactly how to reproduce the vague bug you reported. Never mind that you're paying him 5 times as much as a QA tester would cost you!
If anything slips through your rigorous testing process, your customers will definitely write detailed bug reports indicating exactly how to fix the issue - they would never say "it doesn't work" and leave you a 1-star review that deters potential future users.