Add your revenue streams and expenses to see your net profit or loss instantly. Export the summary as PDF.
Add revenue and expense items, see the net profit or loss update as you go, and export the result as a PDF.
It is a working calculation to see where you stand, not a filed set of accounts. Formal reporting has rules about how and when items are recognised that this does not apply.
No. Everything is calculated in your browser and nothing is sent to a server.
Be consistent, and normally use figures excluding recoverable tax such as VAT, since that is money passing through rather than income. Mixing the two is what makes a total wrong.