The wallet where you can store UTN can be found here: https://access.universa.io
Also, we are planning to release hardware wallet in near future. Mobile wallet is also in the development.
Will a wallet be created for storing UTN coins on the Windows platform? I feel very strong discomfort when storing coins on a "foreign site" online.
We plan to release a desktop wallet, too, in due course. Don't worry, actually, your tokens are stored on your device. You have your contract file with your tokens (unicon file) and your private key (unikey file) which gives you access to your tokens. Store those files securely, especially the private key, and nothing will happen to your tokens. It's preferable to store them offline on a flash drive to enhance security.