hi, my name is George
i have experience in promoting Apps (i'm an Android apps developer, search for Tod Gemphis on GPlay) so i was interested on how to boost my app installs and found a way. On Facebook there is a tool named Facebook Ad Campaigns through which i tested and boosted some app installs and can say it went pretty good. 0.6$/install is a very good price.
i can do this for you, i can promote your app installs.
Keep in mind that this will be real installs, it will be an Ad on facebook on which will click the persons which are really interested in this ad so if they install the app and like it they will keep it.
thanks. hope you'll contact me