Samsung galaxy j7 also known as j7 dual launched in 2015 after that many updated version of this phone launched and currently j7 ruling in mobile market specially in mid range segment.
Its launched at 15000 rupees but today you can buy at 10000-12000 approx.in this price segment j7 is best because of specification and its easy of use.here are specification of j7
J7 sapported 2g/3g/4g , lte & volte is also avilable.screen size is 5.5 inches which is AMOLED and comes with multitouch.front camera is 5 mp with led flash and main camera is 13 mp with led flash.camera quality is awesome.internal memory is 16 gb and external is 256 gb through sd card.rM is 1.5 gb.
Its dual sim phone and dual stand by.
Procesaor which used in phone is Snapdragon 615 Exynos 7580 Octa core and gpu is mali t720 which is good for game.
Speed was awesome when used multi window in single time no heating or hanging problem.other spec which is avilable is wifi, hot spot, agps, usb 2.0, nfc, bluetooth, html 5 etc.
Now we can say that in this price we can not get phone like that.for me there is a single problem is its ram, its not good enough 2 gb or more is better but its ok in this range 1.5 gb is ok.so if you want to buy a middle range phone so go for it.