First, decide how important your side projects are to you. You may have options to avoid handing your apps over, but those options may cost you in the day job. Many places in the US have "at will" employment, which means you can get fired at any time for any reason, and in most jobs if management doesn't like you management can make your life less pleasant.
Second, recognize that you're in a bad position here. You do mobile development for a living, and at night you do mobile development on your own. If you do the same thing for your employer and on your off hours, you're competing with them, and it'll be hard to show you aren't using employer resources. You're much better off if your side projects are considerably different from your employment, so it's clear that your side projects and job are separate, and that you aren't competing with your employer.
Third, you can always negotiate, even when you're working under a contract. Ask for exemption from that for specific purposes, and see what conditions they're willing to accept. This may not work, of course, but it's unlikely to hurt your career. (If I were your manager, I'd be very reluctant to allow you to have independent projects that competed in any way with the company, but much more open to unrelated side projects.)
Fourth, you can check the law in your jurisdiction, because those contract terms are illegal in some places. Don't count on the company having checked to see if all contract terms are enforceable, because they apparently don't sometimes. They may have operations in several jurisdictions, and have a standard contract. They may not have run the contract past a lawyer to make sure it's all legal and enforceable. They may know terms are unenforceable, but put them in anyway. If in doubt, consult a lawyer (and you yourself should consult one anyway if you're interested, given that both your job and your hobby are mobile development). You can use that as leverage in negotiations, or go to court if you want to badly enough, but that isn't going to help your day job.