We use this one. I like it because it has two pockets that are stretchy. I use one pocket to hold my phone and one for ID, Card, Cash, etc. The two pockets help because I dont have to worry about stuff falling out when i do take my phone out of the pocket. Its also nice because it is super flat and most of the time you can not even tell I am wearing it.

i would be cautious with fanny packs only because they can unbuckle them without you knowing or cut the strap from behind without you knowing.