Aiseesoft iPhone Ringtone Maker is the best software to make ringtone for iPhone from your favorite videos/songs and transfer it to iPhone directly.
Aiseesoft iPhone Ringtone Maker supports converting all popular video formats like AVI, WMV, MKV, MP4, MOV, etc. and audio formats such as AAC, AC3, WMA, WAV, MP3 to M4R as the iPhone ringtone, and exports the generated ringtone to iPhone directly. Thus, you don't have to buy ringtones from iTunes.
Exactly choose the part of video or audio files you want to be your ringtone by setting the start and end time, adjust the output ringtone volume and add the fade-in/fade-out effect for better enjoyment.
Edit the existing iPhone ringtones, for example, add/remove/rename a ringtone and then export iPhone ringtones to iTunes/computer/iPhone directly.
Pre-listen to the sound effect to make sure that you get the exact files as ringtone.
Connect more than one iPhone devices to computer at the same time. And choose the device you want to add the created ringtones to.