showing phone no. when calling?

is there way to do or app to show number when person calling me?

You mean vs. the contact name? By default the iPhone supports Caller ID. If you're running on a non-official carrier you may need a carrier bundle to make the formatting work properly and to have it show up in all the right place, but it definitely exists!

yea i have non-official carrier but how?Settings > Phone > Show My Caller ID its on but hidden as active but not working.