With WalletScrutiny.com we focus on impact. As much as "Just build it yourself. It's easy" isn't a good excuse for stealing from the 99.9% of users that will not compile it themselves, offering alternative downloads doesn't fix much. So if you offer the apk on your project's website for download, most users would be more vulnerable due to phishing attacks than if you figure it out with one repository - Google Play Store.

There is one alternative though: Fdroid. If your project is open source, you can publish it via fdroid and benefit from fdroid checking for reproducible builds.