If you send a hand written application letter to my office it will not even pass the first stage, please believe! Unless mwajiri amekuambia explicitly kuwa barua iwe hand written usifanye hiyo mistake. Waajiri wengi wanapenda typed letters for many reasons including they are easier to decipher. Pia siku hizi kwa wingi application na CV hutumwa kwa email, kwa hiyo it makes sense to type out your letter. It also shows that you know you can use the computer for word processing.
Good luck!