hello sir ,
i am monik and first of all lets answer your question : -
1 : according to me best way to achieve this animation is to use Lottie library for animation , which means i can do this by coding . i have some reason for coding because if we use GIF , there are chances that it will not work below android version 4.1 (i said chances because it depends on GIF ) and also it will also increase size of application .
webview is also not best option because if the user does not have internet connection he or she will see error page and i do not like the way it works because there are less options for customization for this situation .
2 : as i am going to do it programmatically i will use android studio. but there are options that we can also make our Lottie animation with adobe after effect thought it will require android studio for implementation .
3 : yes i can do this in 2 days . and also i can start this work right now .
i am monik and i have 4 years of experience in android native , IOS , and hybrid app development . if you have any question you can ask me in chat-box .
i hope we will discuss about this project soon .
Thank You
Monik