Try Walkband for android it's completely free and you can doo many cool things with it. It contains acoustic guitar, drums, drum machine, piano, chords, and a thing to layout tracks. You can also try Trap Drum Pads Guru it's a mobile version of MPC.
I was surprised not to see this dude on your online production tutorials category. He does amazing tutorials for fl studio which range from rudimentary music theory to bass design to setting up fl studio to synthesis to layering and so on. He really does it all, I recommend him for anyone who uses fl studio and wants to get an edge in starting production.