title: Build multiple apps with different assets but using the same code
body: <p>I am currently changing my apps, made with Swift and Java, to Flutter, however, right now I have 5 Apps for android and iOS, all using the same code (5 in Swift, 5 in Java), and, for each one I have different assets, like images, strings, API url's etc. In case of an iOS app I was currently creating different Targets on XCode, with different user-defined variables that i use in the code, and then I chose which target I want to build and send to the corespondent iTunesConnect app. In android I do more or less the same, but using Android flavors.</p>
  
  <p>My doubt is how can I do this in flutter without being forced to create a different Flutter project for each app I want to build.</p>
  
  <p>Any ideas on what approach should I use?</p>