Mobile apps can come preloaded on the handheld device as well as can be downloaded by users from app stores or the Internet. You can find mobile apps on both feature phones and smartphones. The most popular smartphone platforms that support mobile apps today are Android, iOS, Windows Phone and BlackBerry.

Here are five vital skills for those looking to become hot-shot mobile app developers.

JavaScript. If you are a front-end developer for mobile apps, JavaScript is your best friend.
Cross-Platform Development (UX/UI design)
Cloud Computing.
Internet of Things.