I will see what happens in September / October because the hardware announcements often change my plans. Currently the most requested feature not in the next version is the ability to show live workout information on the iPhone (mainly for use by cyclists who mount the iPhone on their handlebars). I may also extend that to allow the app work without an Apple Watch, which would open up a whole new market of potential users.
So if nothing else changes by the time I have handled the hardware releases then that will be top of my to-do list. However it looks a big year for both iPhone and Apple Watch hardware so it may take a few months to deal with whatever is announced.