I know that this is expensive, but if you managed to make your site without any ads, I think this wouldn't be much of a problem.
I love this game. I know I'm a newbie, but I love it. I'm on it a lot, but I travel a lot. I have errands to run, people to visit, and not much time at home. So, I'm online maybe an hour a day? 45 mins? An app would give me access to the site 24/7. My idea of an app based off of a website would allow you to check on your sylesties, nurture your hatchlings/egglings, and to send messages to friends.