Under the Administration of Estates Act 1925, the best right to apply for a grant of representation typically falls to the executors named in the will, provided they are willing and able to act. In this scenario, the testator's ex-spouse is no longer eligible to act as an executor because the divorce effectively revokes her appointment as an executor. The son predeceased the testator and thus cannot act. Therefore, the remaining named executor, the testator's friend, has the best right to apply for the grant of representation. The testator’s niece, being the beneficiary, does not automatically have the right to apply for the grant unless there are no executors willing and able to act. Similarly, the nephew of the son has no right to apply for the grant related to the testator's estate, as his connection is through his deceased uncle’s predeceased son and not directly to the testator’s estate. 

Key Point: When determining who has the right to apply for a grant of representation, priority is given to the executors named in the will, provided they are able and willing to act. Divorce and death of an appointed executor can affect who ultimately has this right.