It is certainly possible to transfer your application to another Bubble account. You can transfer an application on the Free plan from your current account to another by going to the app’s editor, clicking on Settings, selecting the Collaboration tab, typing in the new user’s email in the “Invite a user” field, and clicking “Transfer”.
​
In order to transfer an application on a paid plan, you will need to invite the user as a collaborator instead. You can do this by going to the app’s editor, clicking on Settings, selecting the Collaboration tab, typing in the new user’s email in the “Invite a user” field, and clicking “Invite”. The new user will need to assume responsibility for payment on the application’s plan by going to the app’s editor on their account and selecting the option in the App Plan tab.

For those on legacy plans, please do note that applications cannot be transferred while on a Personal plan; your application will either need to be on a Free plan or Professional and above in order to be transferred to another user.