Refine Google Ads App Targeting

I already run a Google Ads (PPI) campaign for my mobile app, but the keyword and audience setup feels too broad and I’m not seeing the post-install engagement I want. The app itself is finished; what I need now is a specialist to tighten up my existing campaign... (Budget: $30 - $250 USD, Jobs: Advertising, Digital Marketing, Google Ads, Internet Marketing, Keyword Research, Marketing, Search Engine Marketing)