Samsung galaxy j7 is only for Samsung fans and why Im saying this will be justified by the upcoming review.
Design and build quality - The smartphone design is pretty dull and boring and feels like that Samsung is taking inspiration from their old smartphones for design. Build quality feels cheap thanks to low plastic material quality.
Performance - As far as performance is concerned, every year Samsung tries hard to provide worst performance for the given price point and this year also it tries and it won. Im not saying that the processor is bad, the processor is average but because the UI makes it even worse. If you are heavy gamer, skip this smartphone.
UI - The UI is good in terms of looks but on features front, its very bad. There are no special features and for every functionality you have to download apps which will eat up your memory. Also Samsung is very good in preventing its budget phones from getting future android versions so dont expect this either. You may get marshmallow but after that you will not get any future android version like android n.
Battery - the battery life is strictly average and you should carry charger with you if you are heavy Internet user.
Camera - Both the camera modules be it front or rear suffer in both day and low light. The rear camera does not capture details very well. The front camera is average and can take descent selfies.
Conclusion - As I had stated in the starting, if Samsung fan I cant prevent you from buying this piece of garbage but if you are not among the Samsung fans, skip this and go for redmi note 3 or le 2