Really nice concept. I'm interested.
I'm Android app developer with 3.5 years of experience and also worked on algorithms like this app requires.
I've share budget by considering Pyramide app which have few difficulty levels, which challenges the user and also have user friendly design. I short a play store publish ready app. If you wish to implement in your budget, it is also possible with single difficulty level with simple UI.
I'm looking forward to hear from you.
Thank you.