Idea 1: Monthly plans
I was originally very into the idea of a 90 day plan but it is just really hard to keep track of especially for data since Android only has monthly tracking of data usage. Simplify the plan structure to one month plans with the renewal date on the first of the month.
Idea 2: Unlimited throttled data
LTE data is great and I make the most out of it but I'm realizing that since it's so fast, I am using it a lot more. It would be a great feature to allow unlimited data at throttled speeds when you go over your LTE data limit so that basic things like web browsing and email can still be done. I know you have already declined this suggestion in the past but thought I would make it again so that you know that interest in this idea is not going away.
Idea 3: Mobile website/app
Keeping track of my account is much less pleasant than with WIND. The My Account website is very outdated with minimal functions and it doesn't work on mobile. Make that better. It doesn't need to be an app but at least it should be a responsive site with better features.