What are some actionable items you would do, if you were a solo developer and wanting to increase daily download rate of an Android app?

Hi all,

I was wondering, what are some actionable items you will do, if you were to increase the following product daily download rate?

This is our Android notes app product - https://wenote.me , https://play.google.com/store/apps/details?id=com.yocto.wenote

Recently, I have spent some marketing efforts in the past few months, by doing the following.

1. A/B testing screenshots, for various localisation. For most of the localisation, I can get a better conversion rate than my previous's. However, most conversion rate still lower than peer's median. Currently, I lack of idea on how to improve conversion rate further.
2. Using AppRadar as ASO tool (to figure out high volume traffic keywords), by re-wrote app title, app short description and app long description, for English (United States), Chinese (Traditional Taiwan) & Brazil (Portuguese). However, after almost a week, I still do not observe any improvement. For instance, one of the searched keywords I wish to capture is "memo". But, till now, my app in English (United States) is not ranked for such searched keyword - https://play.google.com/store/apps/details?id=com.yocto.wenote&hl=en&gl=US
3. Paid marketing. We solely rely Google Ads. Reason is that, if we try on Facebook Ads, the CPI cost is significant higher (like 10x) than Google Ads. I think the reason is that, Google Play Store is Google's asset. Hence, it will be way cost effective, to advertise via Google's network. We don't see a reason why we need to pay 10x cost, to grab a user.

Even though we have performed the above actions, we still do not see increase in our daily download rate.

May I know what other actionable items we can do, in order to increase our daily download rate?

Thank you.