Jaxx only supports transparent transactions, which is useless because Zcash's transparent tx is just a clone of Bitcoin. Private transactions are not supported, probably due to excessive computing power required.
You're a glass-half-empty kinda guy, aren't ya?
It is at least an HD wallet that does not reuse addresses....so if you send to it from a zaddr elsewhere, you've pretty effectively laundered ownership.
Jaxx is NOT working on the issue at the moment! The constraint is not Jaxx, but the computing power required to perform a JoinSplit transaction. Hardware specs in an average phone won't be able to accomodate private transactions in next several years at least.
Our current development priorities include "Payment Offloading", which will provide a way for low-powered devices to have proofs created by a remote service. You can follow progress here:
"In the coming days, Jaxx intends to further improve its platform by cherry-picking and implementing some of the best properties of various blockchain platforms. As a part of its initiative, the company is already in talks with the creators of ZCash, exploring the possibility of including ZEC shielded addresses into the platform. Its potential integration will further enhance the privacy of the platform’s users."