I like the concept offered by Uniwhales, but before the app was launched maybe the pro version could be used by users for free for the trial period
Yes, there should be a trial release first, so people can judge whether this is really useful for them or not. Certainly to get more interest when the original app is launched. Unfortunately he's only a fan, we can't discuss so much about it if the project owner ain't here 
I hope these "fan" don't have as much information as the owner.