Ive tried three other meditation timer apps and although they may "do " more, to me meditation is non-doing. A timer that allows the phone ringer to be silenced helps achieve non-doing more than more elaborate visiuals or mulitple recordings of chants. The timer bell sounds a bit like a sinigng bowl - other apps reproduce that sound a little better, but this is pleasant enough.
If you find visuals useful in meditation, the app does have some good ones.
2Cats about Personal Om - Meditate / Meditation Timer