easyarabictyping.com

اكتب في العربية - With this tool, you type in Latin letters (e.g. a, ar, etc.), which is then converted to characters that have similar pronunciation in the Arabic language. To give you an example, if you type in 'Sabah el kheer', this will be converted into 'صباح الخير'. Additionally, on clicking backspace a list of candidate transliterations may show for you to select. This makes typing in Arabic easy and natural. There is no need to remember complex Arabic keyboard layout.