You have to disable the Dji Go app otherwise litchi won't work from my experience. Because android has you set a default app to open when the RC is connected the video goes to DJI Go unless it's disabled.
Several people have expressed their methods re this issue - and it is an issue. Bos123 is correct but on my Samsung S2 and Nexus 7 I follow this procedure - start tablet, start P3P, start RC and let in initialise for a few seconds then start Litchi. Works for me!