Fill in the details and the letter is written and laid out for you - with your logo, date, reference number and signature block. The preview is the real PDF, with no watermark.
An experience letter is issued by an employer to confirm that a person worked there, in which role and for how long. New employers ask for it during hiring.
Yes. Use the extra paragraph box to add a line, for example about a project or achievement. It is placed before the closing.
No. The details are used only to draw the PDF. A copy of the form stays in your own browser.