Android Question How to make animated activity backround like uber apps

gif view or video view that fills entire activity ?

Really, that smooth ? And also random color everytime application start , random movement of dots.

I don't think so.
The way i see it, it's like winamp visualization plugin .

Anyone know how to make this with b4a ?

hummm...how about creating some HTML and javascript to save locally and display it in a webview in the backround...When you lanch the app you can write random values in the proper places in the html file before showing it. That might do the trick...not sure though