I have developer a Shopify Remix UI extension application. It is now on my partners account. However, i have a client to which I would like to trasnfer it to and then be able to still work on it as a collaborator. Is this possible? What would be the best approach?
AFAIK, this is something that Partner Support can help with, but you’ll need to contact them directly. When doing so you’ll need to provide the ID for both partner accounts, and assuming there are no concerns, Shopify should be able perform the migration internally
Edit: I believe I misread your post, my mistake. It sounds like you’re actually talking about transferring a custom app to a client, which is a process I’m personally not familiar with. Hopefully someone else can jump in and assist 
Hi @isthatkar
By “transferring” the app to a client do you just mean install the app on the clients store? If it’s a custom app you can generate an install link which your client can use to install the app.
Then you can continue working on the app, and when you want to push a change to your client, you’d deploy a new app version: About app versions