In case anyone comes in here looking for the answer.
NO.
Defragmenting on a desktop or laptop is only useful when the storage is on spinning platters, so the read head doesn't need to go all over the place to find all the parts of a file. Smartphones (and tablets and many newer laptops for that matter) use solid state storage. Not only is it not necessary to defragment solid state storage, it's actually detrimental to the overall lifespan of the storage device as those chips have a limited number write cycles before the media starts to degrade.