When you buy something that only will be helpful when you have a car problem, it may sit on the shelf for some time until it can prove its usefulness. In the meantime, it is supposed to give a reading while checking the resting voltage of the battery section. My Android phone keeps on showing that there is a network issue, even with a strong signal. I contacted the support desk, but I did not get it resolved. I decided to return the item until this has been sorted out.
Bottom Line: No, I would not recommend this to a friend