Re your question on saving costs: If you run it on a single Linux VPS, then I suspect you can get the costs down to 5-10$ per month.
One thing I find interesting is the growth chart: It's linear. But given that the app clearly has some traction, and is viral in nature, how come it isn't exponential?
One thing I find interesting is the growth chart: It's linear. But given that the app clearly has some traction, and is viral in nature, how come it isn't exponential?