Strength training · App review

What's the Best Gym App
for Strength Training?

I've tried most of the gym apps out there. Strong, Hevy, a dozen others you've never heard of. And after years of using them, I stopped making progress — not because I wasn't working hard enough, but because none of the apps were actually helping me train smarter.

So I built my own. This post is the honest take I wished existed when I was shopping for an app: what the real differences are, who each option suits, and the one thing almost every review gets completely wrong.

The thing most reviews miss

Every "best gym app" list talks about features. Exercise library size. UI polish. Integration with Apple Health. That stuff matters, but it's not why you stop making progress.

Friction kills consistency. If logging a set takes too many taps, you stop logging mid-workout. And if the app treats you like a blank slate every session — never learning your patterns, never anticipating your next move — you're left doing all the thinking yourself. That's not a training partner. That's a spreadsheet with a nicer font.

How the big three compare

Here's an honest side-by-side of Strong, Hevy, and Gymbell across the things that actually matter for strength training progress:

The progression engine — and why it changed my training

The feature that made the biggest difference for me wasn't anything flashy. It's called Next Up, and it's the first thing you see when you open a session.

Based on your actual history — your specific patterns, your recent sets, how your performance has been trending — Gymbell predicts the weight and reps for your next set. Not based on generic progressive overload rules. Based on you.

Here's what surprised me about how this works in practice: it's psychological as much as it's analytical. When the app says "try 82.5 kg for 6 reps," you don't want to fail. You at least try. That small act of having a target in front of you, a target that feels earned rather than arbitrary, is what closes the gap between showing up and actually progressing.

Strong has nothing like this. Hevy has moved in this direction, which is worth acknowledging — but the implementation is more basic, and the combination with a conversational AI layer makes the difference in day-to-day use.

AI coaching — and how Gymbell approaches it differently

AI features are showing up in more gym apps now, and that's genuinely good for lifters. Gymbell uses Apple Intelligence to let you talk to the app during or after a workout — ask it to add an exercise, generate a training plan, or analyse whether your current program is balanced.

What makes Gymbell's approach distinct isn't that it has AI — it's how the data is handled. You bring your own API key (Apple Intelligence, Claude, OpenAI, Gemini, or any compatible endpoint), and your key talks directly to the provider. Gymbell doesn't have servers. Your training data is stored locally on your device and synced to your own iCloud — it never passes through anyone else's infrastructure. That's a meaningfully different privacy position from apps that treat your training history as their asset.

Who is Gymbell actually for?

Honestly? Most gym-goers. If you're training with weights and want to stop guessing whether you're progressing, the predictive engine is the best tool I've found — and I spent years looking before building it myself.

One honest caveat

The predictive engine and Next Up feature don't fire on day one. They need data — a few weeks of consistent logging before the patterns become meaningful. If you try it for three sessions and don't see the magic, that's why. Give it a month. The app gets better the more it knows you.

Pricing

There's a one-month free trial with full access to every feature. After that, it's $2.99/month or $39.99 as a one-time lifetime purchase — no tiers, no features locked behind higher plans. Family Sharing is included either way.

Disclosure: this post was written by the developer of Gymbell. The comparisons are based on personal use of Strong and Hevy over several years of training.