How to pivot to mobile app from website

During the last year I've been creating a niche review site and though the traffic is not quite where I want it to be yet, I believe that I will be the leader in this space pretty soon. My competitor has much higher user registration and traffic, and I know it's due to their mobile app. I have finally realized that to truly be competitive, I will have to release a mobile app as well. Regarding this I have a few questions:

1) I am fairly tech savvy and wondering if I should hire a developer or if I should have a go at developing one myself with the Apple SDK. For someone with no experience in this field, is the learning curve manageable or should I not even bother trying to do it myself?

2) The app will be 'sticky' and be used as a reference so users will continue to use it all the time. To monetize, should I go with a paid app, or use iAds/AdMob?

3) (To those with experience in this space) Do you have any critical advice that perhaps you wish you had known before creating and marketing your app?

4) I've put a lot of time and money into the website, and don't feel so great about pivoting to mobile (but I know it is what I need to do based on user feedback). How should/can I use the site to complement the app?

Thanks in advance for your answers/replies.

Sam: Is there a compelling reason to have a native app vs an HTML5 app? If you could leverage your current site and make it "responsive" (ie. provide mobile specific enhancements) then you wouldn't have to go through the hassle of creating an IOS / android app. Also consider that an IOS app requires a 30% vig to apple.

IF you are tech savvy and you understand OOPS then there is no reason not to try and do the app by yourself. If you have a good revenue model on your website then i would recommend making the app as free as it would complement the website.

There are different resources and self read materials available on the net to read about Apple SDK. One interesting link is http://mashable.com/2012/08/01/ios-app-course/ If you want to try and deploy the application over different mobile platforms then do try cross browser mobile application platforms like phonegap (http://www.phonegap.com/). If there is not too much device specific integrations then you can easily create the app using frameworks like phone gap.

If you think this is the biggest differentiator, you should build it. You can hire someone if you have the money. There's no reason to believe you can't build this app yourself until you actually try it.