I know the app seems like it won’t work and has little to no reviews, but it actually works pretty well. You can change the wpm (words per minute), the volume, and even the tone of the pitch. It is, in the end, just a button that beeps when you tap it/hold it down, which is great!
It also has Iambic Keyer mode too :D
For such an easy concept, this is the first app that I’ve found that actually works. Thanks!