I've been hard at work building a weightlifting workout tracking & analytics app. Its main selling points are being iOS native, being a one-time purchase, and being completely private (does not depend on a backend, but still saves data to the cloud).

If it sounds interesting, you can sign up for a waitlist here, it even includes some screenshots: https://plates.framer.website/ (excuse the website being on a framer domain, i promise the app is far more professional)