Settings menu->Options->Main
"Optional transaction fee per kB that helps make sure your transactions are processed quickly. Most transactions are 1 kB. Fee 0.01 recommended."
This message is explicitly put in a label above the amount-textbox, but it is also the tooltip for the textbox. IMO, the tooltip should be something simpler, if it has one at all. If for some reason we keep the redundant tooltip, they should share the same string for translations.
