不用綁定電話號碼/email
可多開account同時在線
可開group
可配合tor隱藏ip

ChatSecure
ios http://itunes.apple.com/us/app/chatsecure-encrypted-secure/id464200063?mt=8
android http://play.google.com/store/apps/details?id=info.guardianproject.otr.app.im

Xabber (an版ChatSecure收msg會delay)
http://play.google.com/store/apps/details?id=com.xabber.android&hl=zh_TW