Vivo Y15S its a most usefull mobile I have ever seen. Guys if you want a mobile which is less expensive and more usefull than Vivo Y15S is the best choice. The main thing of this mobile is its has one unique feature. yes guys the main reason I love this mobile is because of its unique feature. Guys you want to know so listens guys it has secondry lock system yes guys a secondary lock system in which u can store all the information you want to show to your friends or family. And second main thing is that it have gestures typing. so guys I suggest you that if you want a mobile which is less expensive and have more feature than Vivo Y15S is the best not only Vivo Y15S but also other Vivo mobile.