Yes you can! We can build and submit your app to replace existing apps built with another service or any developer. We'll need some information and files from you or your previous developer so that we can proceed.Updating an existing iOS appWhat we'll need: Bundle ID and version number of the app, Apple distribution certificate, certificate's private key, certificate password.Updating an existing Android appWhat we'll need: Package name and version number for the app, keystore file, alias name and passwordYou can forward this to your previous developer or app provider to obtain the information and files we need.In case you can't obtain these, we'll have to submit the app as a new app.