Boostcamp
Why it's on this list
Boostcamp logs RPE (Rate of Perceived Exertion) as a native, set-level field on the free tier, on a 6 to 10 scale in half-point steps, with reps-in-reserve hints in the RPE picker (such as "Could do 2 more reps") rather than a separate RIR field, alongside supersets, drop sets, and customizable warm-up templates. The rest timer, including a per-exercise auto rest timer, is free, and the plate calculator includes 10 free uses before Pro. Strong supports RPE but not RIR and gates its plate calculator behind PRO; Hevy also logs RPE per set on a 6 to 10 scale (an optional RPE Tracking setting); Fitbod and JEFIT fold effort feedback into their own systems (an algorithm and an Elite tier, respectively) rather than exposing it as a reviewable field on every set.
Set-level logging also goes beyond a single fixed target: a set can be defined with a rep range (8 to 12, for example) or an RPE range (RPE 7 to 9) instead of one exact number, and exercises can be logged as timed, for planks, holds, or carries, rather than forced into a reps-only model. That's more structure than a typical fixed weight-and-reps log captures. The interface is also a flat, card-based, modern design across logging, programs, and analytics, built more recently than the UI of several older trackers in this category.
Personal records go further than a simple list: Boostcamp flags PRs with live badges during the workout and keeps Lifetime and This Week PR boards, all free, and Pro adds per-exercise Records and Charts (best set, estimated 1RM via the Brzycki formula, actual 1RM, max set volume, and best performance at 1 to 12 reps). A free in-app Weekly Report summarizes each week of training, and Boostcamp Pro ($59.99/year or $4.99/month annual, 7-day trial) adds Auto Progression; the Strength Score's Level, Max, and Balance views (the 0 to 100 Score view is free, based on the DOTS formula relative to bodyweight, age-adjusted, across 13 lifts in five categories: squat, deadlift, horizontal press, vertical press, and pull); the Muscle Tracker's per-muscle volume heatmap; and Personalized Programs, which build a plan from a short questionnaire. None of Strong, Hevy, Fitbod, or JEFIT offers a comparable cross-lift composite strength score at any price. Building a custom program manually, in-app or on desktop, is free and unlimited either way; the questionnaire-based personalized builder is the part that's Pro-only.
The honest gap: Boostcamp has no native Apple Watch app, while Strong, Hevy, and JEFIT (via Elite) all support Apple Watch logging from the wrist. The closest counterpart is an iOS Live Activity that shows the current exercise, set, and rest countdown on the Lock Screen and Dynamic Island, useful for a glance without unlocking the phone, but it is not standalone wrist logging. For lifters whose primary logging surface is the watch, that is a real reason to look at Strong or Hevy instead.