"truly engage" is too generic and could mean almost anything, "Stop users from uninstalling" is much better

When you write copy go for short, appealing and use frontloading. Tell me what it does. Frontloading text means tell me the important information first. Most people just scan read quickly. You need to capture their attention. Although 'stop users from uninstalling your app' makes it sound like you will prevent customers / app users from making an autonomous choice, bit draconian. The suggestion above of "keep 'em coming back" is nice.

Clear, concise, and something I'd want!

Hey, I get an error message when I click the provided link. I really like what you're working on. It's critical for us product owners. If I thought about how I'd see your product as a branded commercial, I'd look for something to stick in my head. I hope you don't mind that I've proposed an additional tagline for hangam.io..."Keep 'em coming back". Thoughts?