Mobile App Upgrade

I have an existing bi-lingual mobile app with active users on both Android and iOS. The app is simple and does not involve any transactional or customer database management elements. It's a non-commercial (not-for-profit) app meant to give knowledge and information on the subject to the users. The user interface is very basic and I am wanting to give it a proper UX lift. The languages used are English and Arabic, so someone who is familiar with the Arabic language will be very helpful. I expect Flutter to be used for this.