What you can do is make sure that you have the target image on a server and every time you need to update something then you can upload it on the server and keep the same name of your previous target image. So that would work for updating existing image targets and not inserting new target images. For that scenario you would have to rebuilt your app.
I bought two wikitude SDK licences for each iOS and Android.
For now I put every materials inside the application code and release.
However in this way I need to release store-update every time I changed the marker/images
What I want to do is change the marker and image without releasing myapplication like wikitude studio.
Is it possible??