Great app and good user base. Yes, app should be updated as soon as possible to compete other apps of same segment and also to increase avg ratings.
I have done analysis on variety of projects, have deep understanding of Android app development and have hands on experience working with Material design.
If you agree to move ahead, I'm available for development asap. I'm open for chat to know more about exact requirements.
I'll be available around 20 hrs/week for this task.