One of the missing features in Windows Phone Contacts People is ability to find by number. For example if you do not remember the complete phone number but something of starting or end or may be in between, it impossible to find someone like that.
This is something not impossible to implement because I have seen some of the Samsung Phones having this feature but it is just not there in Windows Phone yet!!.
Calling Pad for Number Geeks
True Dialer is a Windows Phone App which just does that. It let you search any person in your People hub using Number which can be anywhere but in sequence.
The app interface is simple numerical keypad. All you need is type in the number and it searches and result is displayed instantly which lists people having those phone number. Next you can tap on any of them and it prompts if you want to call or dont call. If you press call it takes you to the native Windows Phone Dialer else back to the search result.
Apart from this it also maintains a list of calls you made in the History list which makes it useful for users who only want to find people with Numbers when just not sure.
Video Demo of True Dialer : ( Watch on YouTube )
Enhanced Search Feature :
Another feature in the phone which you can use is Enhanced Search which gives you access to many phone numbers around the globe which can be a call center number of a service or an ISP etc. Though useful but then you also allow True Dialer app to do a look up into your phone book as this a op-in Crowd Source Global Phonebook, So unless you are very comfortable with this do not use it.
It can even do this but thats not the purprose but if you you can tap out the name on the dialer (in form of numbers) and it will search your People Hub.
So for example if you want to search for Ashish, I will tap 274 and it will figure out all the combination possible using the words 2 ( ABC) 7 ( PQRS ) 4 ( GHI )