Recommendations for developing a golf group management app for Apple devices

I am using Excel to manage a weekly golf group. Have created multiple worksheets and procedures for the various tasks.

Considering creating an app to replace the "now tiresome and time consuming" weekly tasks.

Now retired, but my career was developing software (specifically MRP, so end user oriented DB solutions). Hence, I know I can learn a programming language and develop solutions.

Multiple procedures including adding/deleting/updating players, signed up to play this week roster/reports, creating teams and scorecards - requires a process to create handicap balanced teams (golfers will understand), tallying team and individual results. Obviously, the app will require a database.

Since I have a Mac, an iPad, and an iPhone you know where my heart is, and I would love to develop the apps for the Mac, and usable on the iPad (although screen size makes it a little cumbersome).

However! I have to consider that someday I will pass the torch to someone else and they may not have a Mac, albeit that "other" well knowns GUI product. (ha ha)

Recommendations? Swift (and pray I can find a replacement in the future who uses Mac or iPad?), Javascript, C++, other?