You could try to contact an Instagram-Model and ask him or her, if he or she could make a picture of there breakfast with there mobile phone next to it and showing your app. I guess, about 20k viewers could see that per "Model".
If your converion rate is about 3% that would be ~ 600 installations.
If you have 10 of these friends, you could have about 6000 installations. Maybe you put your friends into your app, so they have a reason, to download your app as well and show it to there other friends.
The next question would be "monetisation". Do you make your app for fun, than it doesn't really matter, if you got more people to download it. Or do you need your app to perform quite well, to get your investment back? If the second, you could calculate, how much you would invest, to promote your app.
If you have InApp-payment, I guess, your conversion rate is also about 3%, so if your InApp-purchase is about 3,- $ or so, that could be about 378,- $ revenue. (6000*0,03*3*0,7)
But how long have you create your app? Do you know Twitter-guys, YouTuber or other social media people, who have some followers? You could think about Kickstarter, and talk about your App, and maybe these people don't invest in your project, but download it, to try it out.
Also Google and so on, would see, how long anybody tries your app. So only downloading and not deleting is not enough. But I guess, developers have all there own projects and have little time for that. Because we also would have to install 100 apps. Let's say 10 min. with download, try commenting and so on.
1000 min. That are more than two complete working days. It is nearly the same amount you could create a Ludum Dare game and show your app there and there are 1000 people, who possible try out your app.
I guess, your need more someone like a "Let's Player".
