I would do the UI last I would make it look like shit. This is exactly the opposite process of being a web designer or if you have a client and you show them like your first mock up they assume immediately that you've built out the entire back end. They're really my family it's like my cousin my sister my spat like people who were really close to me so it's not somebody who thinks I would do anything. It did fizzle out later but it was helpful for marketing.