Samsung is seeding new security software updates for the 2016/2015 variants of the Galaxy J1 and the Galaxy Grand Prime Plus. All of these updates will install the latest January Android security patches, and are therefore recommended.
The build number for the Galaxy J1 2015 model is J100HXXU0AQA1, the Galaxy J1 2016 model gets build number J120WVLU2AQA1, and the Galaxy Grand Prime Plus build number is G532GDXU1AQA4.
All of these devices are budget offerings from Samsung with very basic specifications. The Grand Prime Plus is the latest of the lot and was released in November last year. It comes with a 5-inch display, 1.5GB of RAM, a MediaTek MT6737T processor, 8MP rear camera, 5MP front camera, and a 2600mAh battery. It runs Android 6.0.1 Marshmallow, whereas the J1 2015 runs on KitKat and the J1 2016 has Android Lollipop on board.
These updates are for the unlocked international variants and must not be installed on carrier locked versions. Before you install the update, make sure your device has more than 50 percent charge, and is on a strong WiFi network.