re: "If I want to hire a freelancer to develop a game app for iOS and Android, what would be the price range?"
The minimum hourly rate on Upwork is $3.00 per hour.
The minimum allowed fee for a fixed-price contract is $5.00.
There is no real maximum for hourly rate or fixed-price fees.
You could pay $20/hour. Or $50/hour. Or $150/hour.
Why is one freelancer charging $5/hour, while another is charging $100/hour?
Do you think their skill level is the same?
To develop a decent game app for iOS or Android, it may be possible to hire somebody to do that for a few hundred dollars. But what if the result is not really worth anything? A more realistic price may be in the thousands.
IF YOU WANT TO SAVE MONEY, then you need to hire multiple different freelancers to do the same task and evaluate what they provide you with. Then continue working only with the ones who provide you with the best value. That may mean continuing to work with freelancers who charge more, because their work is worth more. What if "Fred" works 2 hours, at $50/hour, and gets more done than "Nancy" who works for 20 hours at $5/hour?
Note that Upwork DOES NOT SET the actual rates that freelancers charge. Freelancers decide that for themselves.
If you are asking this question at all, then you almost certainly need to hire an independent project manager. If you don't hire a project manager, and you are not qualified to act as the project manager, then the project manager will (by default) be the lead developer on the project.
The problem with that is: Only about 25% of lead developers are qualified to act as their own project manager. So in 75% of such cases, the project will fail.
