Hi! I wish to have my app developed. It will be for Android and for iOS. I investigated lot, but can't make a decision. Which way is better to have two separate apps or crossplatform one?

If you don't want to spend too much time learning objective c (ios) or java (android), you can use cross platform mobile development framework such as phonegap to make ios and android apps. Although imho it s not as comprehensive as native app but, it does a pretty decent job.

Thanks Sautaja! The reason is that I don't want to learn programming, I want some experts to do it and to give me reasonable advice.

it depends on how complex the app is. Most apps can be developed fairly quickly with phonegap or other crossplatform frameworks. Having an app developed separately means more time and more money. I've done both. There is a level of complexity where it just makes more sense to build completely native on each platform separately, but generally, I'd recommend going crossplatform if it's feasible.