The R6 tactics app is a really good app which is available on iOS and android. It is the rainbow six maps which you can annotate and put the operator symbols down.
Even Rainbow Six Siege is Getting a Mobile Port for Android and iOS
How to REGISTER for EARLY ACCESS to Rainbow Six Mobile (R6 MOBILE) - YouTube
Rainbow Six Mobile android iOS pre-register-TapTap
Confirmed! Rainbow Six Siege is coming to Android and iOS - Crast.net