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DVR recordings can only be viewed from the device where the program is recorded. The Spectrum TV App and watch.spectrum.net does allow access to OnDemand content. As well, your credentials also work for many partner apps, so there are multiple options to view programming using the app.
This feature is not available using a Spectrum leased DVR. However, you can have this functionality by instead using a TiVo device with a cablecard and tuner adapter and the TiVo app.