By default your surveys show a Made in LimeSurvey button at the bottom of the survey page. One global setting switches it off for all surveys on your survey site. The option is available on the Expert, Business and Corporate plans.
Log in to your survey site.
In the left sidebar of your workspace, click Global settings.
Open the General tab.
Scroll down to Show LimeSurvey branding in survey and set it to Off.
Click Save and close.
Note: On the free and Basic plans the branding stays on. See Upgrade your plan and the pricing page for what each plan includes.
Yes. In the editor, click Presentation in the left toolbar and then Theme options. Set Logo to Yes and pick or upload a Logo file. See Theme options and presentation settings.
Yes. The Expert plan adds a white-label domain without the LimeSurvey name. Business and Corporate add an alias domain with your own domain name. See How do I change my survey site domain?