these were all drawn three or four years ago on my phone at the time, which was a Samsung Galaxy Note 2. I really loved that phone and was fully prepared to buy the Note 7 until they pulled it. Stupid exploding phones.
Drawing right on the screen really made a difference for me, and got me hyped about getting a Surface Pro. I'd like to get a Cintiq, but I've never really been in a position financially to justify spending that kind of money (same with the Surface for that matter) so it hasn't happened yet. I moved onto another phone and have gone back to drawing on my desktop tablet (right now a Huion 1060plus, which I don't really like) but I am planning on getting that Surface Pro fairly soon. I'm still deciding on whether it's worth saving up for a Cintiq or not.