Was the 2 day limit just something used to challenge yourself, or did a client actually need a design within 2 days?
I've produced some of my best work while designing at 24 hour hackathons. These types of limitations are fun and motivating, but you could be making some poor UX and development assumptions without proper testing and research.
This app was just for design purpose, not for development. and I actually spent around 3-4 hours on this design, not 2 days.
3-4 hours from start to finish or 3-4 hours on the visual design?