Having a welcome video or video testimonials would be a million times better than using written testimonials about an app that no one has used yet. A video of myself or any other content creators selling their own app, explaining to the downloader why they should download our apps, what separates our apps from competitors, and talking about our features our course, i believe, would be more powerful than a few written testimonials.

Better yet, video testimonials would be better than written. We live in a world were most would rather watch a 30 second video over reading testimonials. People can see written reviews in the app store so seems silly to have written reviews also in the app.