was in the exact same boat-tiny budget, indie app, and Performance Max was a black hole. what actually worked was stripping it right back: one Search campaign, exact and phrase match only on high-intent terms like "habit tracker app", "meditation timer", "focus timer". Turn off Display partners immediately. Broad match is a money pit at that scale.
Set the conversion goal to in-app purchases or registration, not installs. Google will merrily waste your budget on accidental taps if you let it. With a limited budget, tight keywords, one solid responsive ad per ad group, and a landing page that mirrors the search intent are non-negotiable.
Pulled keyword ideas from the search terms report, App Store keyword lists, and niche community discussions (some subreddits I hadn't even considered). ran it through a couple of ASO tools, plus a Reddit monitoring tool that surfaced app-related threads i was missing-those gave me phrases that lifted conversion rates on both the ad copy and the product page.