Nowadays most of the websites are responsive websites. This makes your site looks great on mobile devices. However, it still looks and feels like a website. Matching the color of address bar to your website, gives it a native app-like feel. This improves user experience.

In ionic version 1 you can find modal sliding from bottom to top called as slide-in-up. This is default and there is no option to make it slide from right to left or left to right.