Hello, I am so happy that you asked these questions and gave me suggestions since I am new in UI/UX field. This is my goal to become UI/UX designer as well as coder too.
1. The font I used is Opensans. I will try Roboto font. I'd no idea that it's essential to use android fonts and I will check font weight too.
2. "Mobile Data" and "Wifi" both are tabs where we can only swipe nothing else and to show data and if I remove the bottom and top line, wouldn't it look weird?
3. I will do it with standard material design, it's just that it is hard to learn.
4. The thing is I don't understand how would it look on a phone when the actual app is developed. I hard to guess that are they smaller or not. I did increase size now but you saying it shouldn't be smaller than "46x46" in what sense? "DP" or "Pixels"
5.Rs 497 is not tappable, it is a price of that data.
6.I thought that if a user wants to open it. Just slide it from left to right and it will open from any screen.
I made some changes. I am skeptical about point 2. I removed both lines so it wasn't looking good. So I thought to remove 1 top line and I changed fonts to Roboto and gave little bit stroke also.