All of my applications come about because I need them, so if i can't find an App then i often end up writing it myself.
iSitter wasn't quite that, but it was pretty close.
May 2011, our family of 5 takes a trip to Legoland in Windsor. The trip is at a weekend and we arrange to stay in a hotel on the Saturday night. As is fairly typical for us (2 adults, 3 kids) we can't fit in one room, so we have booked 2 adjoining rooms in the Hotel.
After an exhausting day we arrive at the hotel to find that although we do have 2 rooms next to each other, there isn't actually a door in between them, this is going to be fine for sleeping - we will have a boys room and a girls room - but for the evening this is going to be quite a problem.
Faced with loosing a night with my wife in front of the TV (we have a bottle of wine ready), i start thinking about a technical solution - what if there was a way of monitoring whats going on in the kids room from our room.?
Now as my wife will tell you i go pretty much everywhere loaded with technology, I certainly had multiple iOS devices on me (never know when a app bug is going to need to be fixed). A search through the App Store finds a couple of apps which promise to act as a baby monitor, I organise tethering on my iPhone to get 2 devices onto the same wifi network and download a promising looking app.
I think we got through the evening, but it was a frustrating time with crashes, disconnections and i think eventually the iPhone on the baby end had a flat battery.
So, i mail the author of the app, explaining that it nearly works, if he's not interested in fixing it does he want to give or sell it to me so i can fix it?
Well, there was no reply all weekend, so the next week i investigate what would be required to write my own baby monitor. By the end of the week i've got something kind of working, A colleague at work has a wife who can do some design / graphics for me. And at the end of the 2nd week, i submit my baby monitor to the store.
What do you know, 2 days later the guy with the original app replies, he will sell the app but only for a lot of money. Well by now i've figured out his original app is basically just Apple sample code strung together and I let him know i've just submitted my own app so i'm fine, thank you very much.
iSitter has evolved a lot since then, but its still using the same underlying technology. I wouldn't recommend the baby monitor app space, too many devices in need of a reboot, crazy wifi networks and other things to go wrong - its definitely not a wall to wall 5* review situation.
I will rewrite iSItter totally in the next year, building on what i've learned so watch out for that.