Boostcamp
Why it's on this list
Boostcamp is the only app here that gives a beginner a choice of named coach programs rather than one house template, and all of the main ones are free. GZCLP (Cody Lefever, 3 or 4 days a week for 12 weeks) has been joined by 39,415 lifters on Boostcamp and holds a 4.36 rating from 5,641 ratings. Next to it sit the Greg Nuckols Beginner Program (3 days, 12 weeks, in Strength and Hypertrophy variations, joined by 14,117 lifters), Jim Wendler's 5/3/1 for Beginners (3 days, 8,537 joined), Phrak's Greyskull LP (3 days, 8 weeks, 5,872 joined), the r/Fitness Basic Beginner Routine (3 days, 12 weeks, 3,298 joined), and Justina Ercole's Functional Strength 101 (3 days, 8 weeks, 3,564 joined). The /beginners page collects them in one place.
Whichever you pick, every set, rep, and weight is already planned. You open the app, it shows today's workout, and when you hit your reps the program raises the weight for next time on its own, with exercise demos in the app so you can check how a lift is done, and rest timers and a plate calculator (both free with no usage cap) so you aren't doing bar math between sets. Logging is simple enough to ignore RPE entirely on day one, and RPE and RIR are there on every set once you want them. Personal records and estimated 1RMs update automatically.
Where Boostcamp is not the leader: StrongLifts has the higher App Store rating and a native Apple Watch app, and Starting Strength goes deeper on coaching cues for the core barbell lifts. Boostcamp's advantage is what comes after the beginner phase: the same free 11,000+ program library (99 of its 132 coach-designed programs are free) and a custom program builder with no cap, so your history carries over when you graduate. Boostcamp Pro ($59.99/year with a 7-day trial, or $11.99/month) adds 20+ exclusive coach programs, the Strength Score, a per-muscle volume heatmap, and personalized programs; a beginner doesn't need any of it.