Why my application doesnt get any downloads?

[AC Question]

my google play applications dont get any downloads, i have the same number of downloads like some ****y app's with only 2-3 images. i think i builded some nice stuff and i dont understand why i dont get any traffic i published app 15 days ago and i got 150 downloads total. and some apps i am seeing on google play make 50k in 10 days even faster... give me some advices and any help is welcome.