Systems and methods of modifying manifests for applications

A server system hosting one or more virtual client devices, each virtual client device corresponding to a remote physical client device that plays back video content received from a content server, the server system comprising one or more processors and memory storing one or more programs for execution by the one or more processors, the one or more programs including instructions for:

• transmitting from an application executing on a virtual client device of the one or more virtual client devices, through a remote physical client device, a request for a manifest;
• receiving a manifest received by, and forwarded from, the remote physical client device;
• determining whether the server system is authorized to modify the received manifest;
• in response to determining that the server system is authorized to modify the received manifest, requesting additional content to modify the received manifest;
• modifying, including adding, removing, or replacing, listed content in the received manifest to generate an updated manifest;
• sending the updated manifest to the application at the virtual client device, wherein the application processes the updated manifest;
• and
• sending, to the remote physical client device, an instruction to request the additional content.