Need a Mobile App for Gym Workout Tracking and Progress Charts

I'm looking for a developer to build a mobile app for tracking strength training at the gym. The core idea is simple: I want to log every set during a workout — exercise, weight, and reps — quickly, without a messy spreadsheet or an app that doesn't match how I actually train. Right now everything goes on paper or in random notes, and there's no real picture of whether I'm getting stronger.

Beyond logging, the app should turn that history into a weekly training plan, spreading exercises across the days I choose and adjusting suggested working weights as my numbers improve. I also want a clear view of progress over time for each lift, so I can see whether my squat or bench press is actually moving forward month to month, not just guessing from memory.

I'm open to iOS, Android, or cross-platform, whichever gets a solid result fastest. A local database is fine to start, cloud sync can wait. Please share examples of similar apps you've built along with a rough estimate and timeline.

What matters most:
— Fast set logging during a workout, minimal taps
— Automatic weekly plan from my exercise list
— Progress charts per exercise: weight, reps, estimated one-rep max
— Manual editing and reordering of the plan
— Clean interface that works with sweaty fingers