I worked on building the website (the apps came about a year later using Cordova so I could utilise my HTML/JS skills) in evenings and weekends for about 4 months. Not all of that was development, some of it was speaking with third parties I needed to get the product working.
The first paying customer got a full refund, because, of course, it didnt work properly, but the most valuable lesson I learnt was just to deploy something and fix it ad-hoc, NOT wait for it to be perfect/feature complete.
I had low expectations, and I didn't quit my day job, so it was low pressure "lets see what happens"
Spending time making the website SEO friendly meant I didn't have to spend a penny in advertising for the first year as all of our traffic was organic. It wasn't until the annual revenues were around £400,000 that I started to spend ANY money on advertising.
Basically how do you get started with such a venture as yours?