Works … kinda
In practice, it makes spotting typing errors difficult and deleting back is a fiddly affair.
If there’s a clear all or clear last entry function I can’t find it, and I also can’t find a way into the program’s menu on the watch - firmly pressing the screen does nothing.
Response from developer
Apologies for not replying sooner. Please try the newest 4.1 version of the app, it should correct the context menu problem. In the new app you can press and hold for a bit anywhere on the keypad to display the menu, or press and hold for a bit on the running total number to clear-all. You can also always swipe left to quickly erase the last entry. In the menu you can select the layout that has biggest possible keys, so you can give that a try also.