I am currently designing an application for Android and iOS. I like Google's Material Design and use of colors.
Can I use the same style and look & fill for iOS apps except the navigation system of iOS? Or are there any specific points for iOS like material design has for Android?
Apple has the iOS Human Interface Guidelines, which set some limitations on design but they shouldn't prevent you from implementing material design in your app.
The only real limitations you have to implementing material design on iOS are technical. The built-in iOS UI elements have varying levels of possible customization. Some are limited to changing fonts and colors. You can always implement your own custom UI elements though. Obviously creating your own custom UI elements can be a lot more time consuming than using the ready-made iOS elements so you need to weigh up the benefits of each case.
Google's own iOS apps have now (I believe) all been designed with material design principles showing you that it is possible.
It is possible, but it would make development more complicated. Using native design elements will save the developers time, because they won't have to make a lot of custom elements.
Another point you would like to take into consideration are your users. They are used to the design language of their operating system. iOS users will be less familiar with Android design elements. This might give them a harder time to understand the app and the experience will be less natural.
Best is to make separate designs for Android and iOS.
