10 Best Mobile Courses are listed below, we think following online courses are the way to learn IOS/Android fast :

Sr.No Course
1 The Web Developer Bootcamp
2 Angular 7 (formerly Angular 2) – The Complete Guide
3 https://www.udemy.com/the-complete-javascript-course/
4 Modern React with Redux [2019 Update]
5 Build Responsive Real World Websites with HTML5 and CSS3
6 The Complete Android N Developer Course
7 Android Java Masterclass – Become an App Developer
8 iOS 12 & Swift – The Complete iOS App Development Bootcamp
9 iOS 11 & Swift 4 – The Complete iOS App Development Bootcamp
10 UI/UX design with Adobe XD: Design & Prototype a Mobile App