Ktor
Kotlin
Micronaut Framework
vert.x
Gradle
Retrofit
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Spring Framework
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 250 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.
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, Ktor seems to be more popular. It has been mentiond 34 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.
In one case, early on, a team had been developing a new service using Ktor, a Kotlin based framework designed for building asynchronous applications. This service provided some core data for the org so we knew it was important to get them into the Supergraph. They, of course, didn't want to redo all the work they had done up to that point so we lent them an engineer from our team to build context on their service... - Source: dev.to / 4 months ago
Ktor: Networking and communication. - Source: dev.to / over 1 year ago
Kotlin / Ktor: Ktor is a Kotlin framework that allows developing HTTP APIs. Itโs somewhat equivalent to Express or Fastify in Kotlin. One of the advantages of the Hypermedia approach is that it allows development in a language other than Javascript, and I took this opportunity for these demos. - Source: dev.to / over 1 year ago
If you want to learn more about Ktor, visit this site. - Source: dev.to / almost 2 years ago
To make requests to Notion's API, we will work with Ktor to instantiate an HTTP client on our app. - Source: dev.to / about 2 years ago
Kotlin - Statically typed Programming Language targeting JVM and JavaScript
Micronaut Framework - Build modular easily testable microservice & serverless apps
vert.x - From Wikipedia, the free encyclopedia
Gradle - Accelerate developer productivity. Gradle helps teams build, automate and deliver better software, faster. DocsExplore the documentation of Gradle. Find installation ..
Retrofit - Retrofit is a type-safe HTTP client for Android and Java.
Javalin - Simple REST APIs for Java and Kotlin
