Paul has a Samsung Galaxy S4 phone that won't update or download apps. He's been told it's too old. Leo says it may be, which is too bad because it runs just fine. Paul could root it and install a custom version of the recent Android OS on it. He should go to XDA Developers and search for the exact model of his phone. It's not an easy hack, and he should follow the directions to the letter. Or he could upgrade. He'll likely get a good deal on a Galaxy S7 or a Note 7.
What about Motorola? Leo says he has some misgivings on the Moto Z, since it doesn't have a headphone jack. It has poor battery life as well.