U

iOS product

Added August 14, 2026

Underdog — Turn heart rate zone minutes into weekly league points

Visit Underdog

About the product

Underdog is an iPhone app that turns time spent in heart rate zones into a weekly competition. It reads heart rate and workout data from Apple Health, recorded by an Apple Watch, chest strap, or other connected sensor, so nothing is logged by hand. Every minute in zones Z1 to Z5 earns points, and higher zones score more. Scoring uses heart rate as a percentage of a personal maximum, so different ages and fitness levels can score the same. Points feed weekly leagues from Bronze to Diamond, with promotion, relegation, and a weekly reset. Private leagues use an invite code. Free on the App Store, with no ads.
0 recommendations

Recommendations are a community signal, not a verified count.

Share Underdog with your network.

For product owners

Promote Underdog

Every listing gets one post to our X and Threads followers. It is seen once, then the traffic stops. Promotion keeps Underdog in front of people instead.

  • Back in the X and Threads rotation. Underdog gets posted again instead of once.
  • A promoted slot on the AppRater homepage, carrying a Promoted badge.
  • A labelled spot in the weekly email to AppRater subscribers, one promoted app per issue.
  • Stays on the first screen however old the listing is, while new submissions push everything else down.

Monthly promotion

$14USD per month

Card, Apple Pay and more, through Whop. Starts straight away.

  • Cancel any time from the Whop account you paid with, or email [email protected] and we will do it.
  • The promotion starts straight away, no waiting on us.
  • Whop handles the checkout. We never see your card.

Questions first? Email [email protected].

For ownersOwn Underdog? Add a deal or post a role, and it shows up right here.

Community notes

Feedback & updates

Start the conversation
No notes yet

Have experience with Underdog, or something new to share? Add the first useful note.

Keep exploring

More for iOS

P

Padel Pointer

iOS

Padel Pointer lets you score matches on Apple Watch and review them on iPhone. Tap to record points on your wrist, follow the server and court side, and undo scoring mistakes. After the match, review your results, momentum, service performance and match history on iPhone. You can also log matches manually without an Apple Watch. Match history syncs privately through iCloud. Built by independent developer Alex Dernie and used by over 14,000 padel players, Padel Pointer is available in English and Spanish, free with optional Pro features. Download for iPhone and Apple Watch: https://apps.apple.com/app/id6757132333

View product →

M

Mooji

social

Mooji was built to help us feel a little less lonely. We're all looking down at our screens, consuming and trying to connect while isolating and reducing our lives to posts. All we really want is some quality time and acknowledgement from the people who matter to us. That's why we built Mooji. It's a fun way to share where you are, what you're doing, how you're feeling, or what you're up for from your Apple Watch. My partner and I use it to know when one of us is headed out to pick up the kids, or if one of us is having a hard day. At Mooji, the team and I use it to know when we're working and when to leave each other alone. It's been a great little tool for staying close and finding time together with close friends and colleagues, and we hope you'll find enjoyment from it too.

View product →

F

FitMe

fitness

FitMe: 10 Minute Workout at home is the best home Lazy workout app designed to help you lose weight in 30 days by doing 10 minutes of daily exercise at home and staying fit. Get Free Customizable plan and diet plans in this home workout app.

View product →