ObjectBox
Realm.io
Microsoft SQL Server Compact
CompactView
UnQLite
VoltDB
HSQLDB
NuoDB
RepDB
ObjectBox is a super fast database and sychronization solution, built uniquely for Mobile and IoT devices. ObjectBox is uniquely designed for small devices, so it is the ideal solution across hardware from Mobile Apps, to IoT Devices and IoT Gateways. It is the first high-performance NoSQL, ACID-compliant on-device edge database. Plus, it's built with developers in mind, with easy to use code that takes minimal time to implement.
ObjectBox supports Java, C/C++, Go, Kotlin, Swift and Python. Running on Android, Mac/iOS, Windows, Linux, Raspbian & more.
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.
ObjectBox 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, ObjectBox seems to be more popular. It has been mentiond 9 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.
Need to sync your MongoDB database and your offline-first apps? In this tutorial, we'll walk you through setting up an end-to-end demonstration of bi-directional data sync between local ObjectBox databases on client devices and a MongoDB Atlas cluster. Together, we'll build a system that ensures offline-first functionality while keeping data in sync across devices and databases. - Source: dev.to / 6 months ago
It would be great to have the vector database run on the edge / on-device for offline-first and privacy-focused. https://objectbox.io/ does a good job of this but are there others? - Source: Hacker News / 11 months ago
When I first attempted to publish to F-Droid, I experienced several pipeline issues. After reading through the pipeline logs in GitLab, I realized that my application's database (ObjectBox) was not entirely FOSS compliant and was causing build failures. The following day was spent migrating my app to Room. - Source: dev.to / almost 3 years ago
I would focus on Kotlin instead of Java, there's really no point in sticking to Java at this point. And when it comes to databases, some local ones that are pretty easy to get into are Realm and ObjectBox, SQLite can definitely be a bit overwhelming at the beginning. Source: about 3 years ago
Just to add to this, there's also Realm and ObjectBox as alternatives. Source: over 3 years ago
Realm.io - Realm is a mobile platform and a replacement for SQLite & Core Data. Build offline-first, reactive mobile experiences using simple data sync.
Microsoft SQL Server Compact - Bring Microsoft SQL Server 2017 to the platform of your choice. Use SQL Server 2017 on Windows, Linux, and Docker containers.
CompactView - Viewer for Microsoftยฎ SQL Serverยฎ CE database files (sdf)
UnQLite - UnQLite is a in-process software library which implements a self-contained, serverless...
VoltDB - In-memory relational DBMS capable of supporting millions of database operations per second
HSQLDB - hsqldb: Full-featured 100% Java ORDBMS
