iOS has a built-in call block feature that allows users to block any number from calling or texting their iPhone, iPad or iPod touch. Blocking and unblocking any number using this iOS functionality is fairly easy. While it is a great feature, it is still very limited. Sentinel tweak increases the power of the call block feature of iPhone by displaying a call history of numbers that tried calling you and were blocked by the device. The tweak shows the number, number of times you received the call, as well as time and date for each individual call.
In addition to that Sentinel also comes with an option that when enabled allows users to see a notification banner whenever a call is blocked from a number in their blocked list.
Perhaps the most useful feature of this iOS tweak is that users get the ability to block all calls coming from ‘Unknown’ numbers. This means any call that does not show the number of the caller will automatically be blocked. The tweak will show it on the history page along with date and time it was received.
The developer also plans to include the ability to see the blocked history for Messages coming from numbers that are in the blocked list of iOS.
You can download Sentinel tweak from Cydia for $2.99 . It works with iOS 8 powered devices.