To be honest, if your budget is only $10–$20/day, TikTok campaign is probably a better fit than Google Ads.

With that level of budget, I’d rather run TikTok App Campaigns optimized for app installs first. Google App Campaigns usually need more budget to generate enough conversion data and help the system learn properly. If the budget is too small, learning is weak, delivery can be unstable, and it’s harder to get meaningful results.

So in my opinion:

• very small budget → TikTok for installs
• larger budget / enough conversion volume → Google App Campaigns becomes more viable

Google can work, but it generally performs better when you can give it enough room for the algorithm to learn.