Strong in short
A plain log with an Apple Watch app and a one-time Forever purchase. The downside: the free tier caps templates at 3, and we found no import from other apps.
Liftosaur in short
Fully scriptable progressions, with free Hevy CSV import and CSV and JSON export. The downside: apple Watch, graphs and the plate calculator need Premium, and there is no Strong import.
Free tier and price
Strong free tier: 3 workout templates and unlimited saved workouts. Paid: pro: $4.99/mo, $23.99 or $29.99/yr, Forever $79.99 or $99.99 (US App Store entries are inconsistent).
Liftosaur free tier: programs, editor, logging, history, import and export, measurements and sharing. Paid: premium: $4.99/mo, $39.99/yr or $99.99 lifetime (US App Store).
Prices are the US App Store listings as of the check date, and some listings show several entries without labelling the billing period, so confirm in the store before paying.
Switching between Strong and Liftosaur
Moving your data. Strong: Exports CSV; no import found. Liftosaur: Imports Hevy CSV; exports CSV and JSON.
Watch support. Strong: Apple Watch (watchOS 10+); no Wear OS app mentioned. Liftosaur: Apple Watch (Premium only); Wear OS not found.
Ads. Strong: Not verified. Liftosaur: Not verified.
If a game is what you are missing
Neither app has a game layer. We make GYM RPG, which logs the same sets, reps and weight and adds XP, a skill tree and a party boss. It is not a drop-in for either app, because we have no import tool and you would start fresh.