...
The default landing page for opFlow displays the Top 10 App Sources as shown in Figure 2 below. This shows the applications that are generating the most flow data displaying their Source, Application, Bits, and Pkts. In this example, these sources are mostly coming from known servers and routers having conversations with each other. However, the application generating the most Bits is clearly Other. Other is defined by all of the other applications that are not on the Top 10 Apps list which in this case is quite a lot. The Top 10 App Sources default view can be used to detect anomalies as well. If you do not recognize a Source or Application or notice that the Other source has a larger packet count than average then this is cause to investigate. To get a clearer view of all the applications that are grouped in Other, the Conversation Summary view is recommended. If you wanted an application that is defined in the Other category to be recognized as a known application by you, you can create a Custom Application. Assigning Custom Applications to known flow data can help gain insight into your network and make it easier to notice when an anomaly in present.
Custom Application creation is detailed Here: Creating Custom Applications
...