
KaiOS
LineageOS
Android
CopperheadOS
GrapheneOS
Ubuntu Touch
Android Nougat
Sailfish OS
RepDB
RepDB is a one-time-purchase exercise dataset for developers building fitness and workout apps โ not a subscription, not a rate-limited API. You download the data once and own it: JSON (and SQLite on the higher tier), WebP images, and full EN/DE/ES translations, with no per-request billing and no dependency on our servers staying up.
A free tier includes 400 exercises with flat-style 512ร512 images, attribution-licensed for commercial in-app use. The Starter tier ($199) adds the full catalog in classic white-background style. Standard ($399) adds transparent 1024px images, looping animations, exercise relations (similar/progressions/regressions), workout templates, and embeddings โ exclusive to that tier.
Every exercise includes muscle-group highlighting, equipment/muscle icons, MET values, and safety/goal tags. Compared to GIF- or JPG-based competitor APIs, RepDB images are transparent WebP with no watermarks, so they drop into any app UI without a white box around them.
KaiOS
RepDBRepDB's answer:
RepDB is sold as a one-time download, not a metered API โ you own the JSON/SQLite data and WebP images outright, with no rate limits, no per-request billing, and no risk of the vendor cutting off access. It's also the only dataset in this space with EN/DE/ES translations, transparent (alpha-channel) images with no watermark, muscle-group highlighting, safety/goal tags, and looping animations on the higher tier.
RepDB's answer:
RepDB grew out of a consumer workout app its creator was building solo. Sourcing exercise images and data meant either paying for a subscription API with usage caps and no caching rights, or producing everything from scratch. The illustrated, multi-language dataset was built for us first, then split out as its own product once it became clear other indie developers had the same problem and preferred to buy the data outright rather than rent it through an API.
RepDB's answer:
Most alternatives are subscription APIs โ you pay monthly, you're capped on requests, and ExerciseDB's terms of use explicitly forbid caching or storing the data at all, so every image render is a live paid API call. RepDB is the opposite: pay once, download the files, self-host with zero ongoing dependency. It's also the only option offering true DE/ES localization and transparent images instead of a white box behind every exercise.
RepDB's answer:
Solo developers and small teams building fitness or workout-tracking apps (iOS, Android, web) who need licensed exercise images and structured exercise data, but don't want to build their own media pipeline or depend on a rate-limited third-party API.
Based on our record, KaiOS seems to be more popular. It has been mentiond 2 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
What website did you go to? KaiOS is not dangerous. I'm dubious that their official site (kaiostech.com) would have trojans or malware on it... Source: over 2 years ago
LetsEncrypt ISRG Root X1's IdenTrust DST Root CA X3 cross-signing has come to an end. This means that any device/browser (including KaiOS devices) which doesn't yet trust the ISRG Root X1 will no longer trust any site with a LetsEncrypt certificate (which, by the way, includes kaiostech.com!). Source: almost 5 years ago
LineageOS - Operating system for smartphones and tablet computers, based on the Android
Android - Android is an open source mobile operating system initially released by Google in 2008 and has since become of the most widely used operating systems on any platform.
CopperheadOS - Secure Android built for encrypted and secure phones by a privacy focused company. Available as security-centric and privacy focused Google-free Android for the latest devices. Fully integrated with the latest IDS and MDM enterprise technologies.
GrapheneOS - GrapheneOS is an open source privacy and security focused mobile OS with Android app compatibility.
Ubuntu Touch - Read more about Ubuntu Touch. Our free and open source mobile OS is made and maintained by UBports! We care about your freedom and privacy.
Android Nougat - Android Nougat is the seventh iteration released by Google for the Android Operating System.