Android : Catch all http requests from an app and Edit header and Forward -

i want catch request android app internet , edit header information. example want add header field host. forward internet. how can achieved. ideas this: 1. create external app purpose , leave run in background task. 2. edit app that. i.e embedding handler app. don't know how embed handler android app. there opera mini versions handler option in internet.

please give me suggestion this. thank in advance. because know stack overflown solutions.