To remove the 'Powered by Wishloop' logo, simply go to your main dashboard screen - Click on your profile menu from the top right of the page and click on "Account"
Then Select the affiliate tab, as shown below:
From here, you can disable the "Powered by" message entirely, or you can keep it enabled and insert your affiliate link in to the message.
The latter option will enable affiliate commissions on any customers referred via any of your campaigns. (You can keep track of these via your affiliate dashboard).
Please note: Users on trial accounts cannot remove the logo, only paid subscription holders will be able to do this. However any user can become an affiliate.
See also: Wishloop affiliate scheme overview