Earlier quoted context omitted.
It's nothing to do with how much space it will take up. The problem is that, as a user, I would be very suspicious of a 100MB countdown timer app. I would think that either it's got some kind of adware in it, or just that it's incompetently designed.
>as a user, I would be very suspicious of a 100MB countdown timer app You mean as a developer. Your average 'user' does not know or care how big an app 'should' be.
A significant number of users would notice an app being dramatically larger than it ought to be. I've seen a lot of reviews like "why the hell this app over 100mb??!!1". There is a huge spectrum of technical competence between "I don't have any sense of what a megabyte is" and "Developer".