Confused

My music teacher told us about getting tuners and metronomes on our devices, so I looked around for the highest rated free app. I first downloaded insTuner, and I loved it. But it didnt have a metronome. I looked some more, I found this and got it. Im a bit dissapointed. I still am very confused on how to use it. Is there a "help" button anywhere? I couldnt find one, and for now am switching back to my old app. If you are reading this and know how to use it without the purchase, please help a gal out!
~Derp Head

Yes Im a Derp about Metronome Tuner | Practice+