Samsung promoting their 'TIZEN' OS by this phone. Tizen looks like a developed version of Samsung's 'BADA' OS, with some new so called smart features and a new UI. For apps and games we have to visit TIZEN Store which is pre-installed in this device. Most of good apps and games are 'pay n use'. Most of the free apps are almost useless. Internal Storage is 4GB from which 2gb occupies by system. PROS: i) Screen & Touch: Touch is great. There is lack of sensor. so no option for auto brightness. Screen resolution is good. ii) Sound: Sound is good. iii) Tizen Store: Some useful apps are available on store. iv) Camera: 3.1mp camera is good. front camera is also nice. v) Smooth UI: UI is smooth(but smoothness is not everything) vi) Some apps are movable on SD Card. CONS: i)Tizen Store: Tizen Store is a place of wastes. I can't find any descent photo editing app there. Only WhatsApp available. Hike , We Chat and other messengers are missing. Not even that, we can not use WhatsApp without installing an another app called 'ACL' This ACL occupies almost 155mb on internal storage. ii) Hanging Problem: Hangs while playing game or some high resolution videos. iii) Back Cover: Back Cover attracts dust easily. iv) MP3 Player: Although sound is good, but there is lack of equalizer. v) GPS: Gps is too slow(or useless) to use. I cannot find my location after waiting for 15 minutes. vi) Ultra Power Saving Mode: this is the main attraction of this device. Ultra Power Saving Mode is nothing but a marketing gimmick. Cause, by enabling this we can not explore all features. This APP saves power with a simple UI and giving permission to access limited Apps. In any phone we can save power by this process. No one needs a APP for that. Verdict: if you are former Android user, don't ever think to buy this.