- No. Depending on where you are in the world it's illegal to discriminate on age. Most (sensible) people care about talent and potential.
- Not really. People change careers all the time. If you switched from being a pig farmer to a app developer, it might be a little unusual - but going from one high-tech industry to another isn't strange.
The best advice I can give you is to start a portfolio. When I look at hiring developers, the first thing I want to do is play with their apps. That speaks more to me about you than your age and background.