Yes. In fact, a lot of customers use more than one sensor in a wide variety of ways.
There's no set limit to the number of sensors you can pair with a single mobile device. Some customers use two or three sensors while others have a dozen or so sensors simultaneously with their one phone.
Also along these lines, a single sensor can simultaneously pair with multiple mobile devices.
If you plan to use your sensors in conjunction with a SensorPush WiFi Gateway, same general rules apply. There's no set limit to the number of sensors you can pair with a Gateway. Also, you can have multiple Gateways on one account. They can be in the same location or they can be in separate locations.