Jaxx is a multiplatform multicurrency wallet. The private keys are stored on your device. It has a beautiful UI, is really sleek and easy to use, and has shapeshift built in. What's great about Jaxx is that it supports every major platform. Desktop clients available for Mac, Windows and Linux. Mobile clients available for iOS and android, and hardware wallet support coming soon. Jaxx is completely open source, so you can check exactly what the application is doing. The jaxx team also is actively adding new coins and one of their missions is to "unite" cryptocurrency and offer a platform that is safe, easy to use and has wide support.