Instagram + admob && startapp = = $$

Hey , guys I'm new in cpa (instagram+ogads) , I have a few account running on a vps + proxy .. promoting ogads CPI offer , I'm earning 1$ a day .. that not a big deal ..

I'm about to try to promote my own apps ... they aren't on the google play store I'm thinking to upload them , and send trafic from Ig ... my apps will be monetize with admob and startapp ads ..

any one have try that before ? also I'm having doubt if the users will download my app ...

any recommendation ?