Not a bad little China built phone. However, Sichuan Koobee Communication Co.,Ltd needs to make a few improvements. 1) Battery needs to be a minimum 5000mAh or offered as an option (even if a different back plate is required as with the older ATT SM B780A Rugby 4) since the stock 3300mAh battery drains fast, even with data turned off. 2) The blocking feature of a telephone number does not work. 3) Forcing an app off does not work, especially if it is a Google app. 4) Needs a cleaning/optimizing app such as the 'Smart Manager' with TCL , 'Device Care' with Samsung, or even 'Norton Clean' version 1.5.1.102. Fortunately, if the browser Vivaldi app is installed instead of Chrome which can then be disabled or uninstalled using ADB, a user can go into settings and clear the history and cookies set from the Play Store and other accessed Internet sites. 5) Like most android phones, apps such as facebook and youtube come pre-installed and should be uninstalled to improve performance and battery life. Most the other apps that have ads and trackers can be replaced to improve privacy in addition to performance and battery life. The koobee k100 would then be a great little phone.