Can you help me to create ringtone for iPhone?

You need no extra software if you want to convert your favorite song to a ringtone. The only thing that you need to do this is your iTunes. The first step is to select the song of your choice on iTunes and right click on it and go the Get info of the file. Now select options from the menu which is on the top. Now change the stop time for the file to 15 seconds or anything that suits you or how long you want it to be but ringtones can't be longer than 30 seconds so keep that in mind. Now go to the advanced tab in the iTunes menu and select create AAC version. Now you just have to delete the file after stop time. So go to get info options and delete your stop time setting or the song will not play after that point in future. Now find that file in folder and change its extension from .m4a to .m4r to do this just rename the file. Drag drop that file on desktop and delete the other one from the iTunes. Now you can transfer and use this file as your ringtone.