Actually, you are going about as fast as you can. It’s theoretically impossible to gain more than two levels in a day, so 63 in a month is pretty darn good.
Just focus on learning and the experience will add up. Renshuu is a learning app, not a game, and just gaining levels is no guarantee that you'll remember what you've learned in the long run. As long as you keep at it and focus on the content (and practicing outside of the app too!), not on points and coins, you'll get plenty of levels.
Your average is 1.5/day. You can get that closer to 2, but that's kinda the limit. We're talking averages, not bursts due to low/no activity. I'm at 1.98/day and don't really see a way to go faster. And this is great, because I'm actually studying instead trying to power-level... which I would absolutely be doing if I could.
