To help myself at swim meets I created a stopwatch (for Android) with almost every functionality an expensive physical swimming stopwatch has (like stroke rates). you can operate the entire stopwatch with the volume buttons of your phone. This means it works just like a physical stopwatch! It is 100% free and without any advertisements.
It would be very cool if you guys could try it out and give me some feedback. It is totally without obligation so if you are not interested, not a problem at all! 😊. This is the link to the app: Stopwatch for swimming