The cable is coiled and black on one end and grey on the other. The black end goes into your microphone and the grey end goes into your smartphone
Despite being sold on Amazon as an iPhone accessory, this should work with most modern Android smartphones. Do your research though I as some older Android phones don't work with TRRS connections properly.
I use the Open Camera app to record videos with external microphones. With my VideoMicro mic attached I was heard a significant improvement in my audio.
There are many cheaper generic TRS to TRRS cables available online, but for the price of the Rode SC7 I think it's worthwhile buying one from a respectable brand.
Check out my video to see me using the Rode SC7 with the Rode VideoMicro. Be sure to post a question if you are unsure of anything :)