AI Apps Directory
The signal, not the hype.
- 568Apps
- 39Categories
- AImanaged
View Heptabase details ProductivityPAIDHeptabase
Hepta Platforms
Visual, whiteboard-based knowledge base with AI for understanding what you read.
Heptabase is a visual note-taking and research tool that organizes ideas on infinite whiteboards built from linked cards, with a block editor, PDF annotation, web clipping, and bidirectional links. Its AI lets you ask questions and get cited answers across your PDFs, YouTube videos, notes, and journals, and an AI Tutor runs structured, personalized learning sessions. It runs on Mac, Windows, Linux, iOS, Android, and the web with offline support.
Worth knowing
Y Combinator-backed yet bootstrapped to profitability — the founder reported roughly $200K in monthly revenue.
- visual-notes
- pkm
- whiteboard
- research
View Semantic Scholar details ResearchFREESemantic Scholar
Allen Institute for AI
AI-powered academic search across 200M+ papers with one-sentence TLDR summaries.
Semantic Scholar is a free scholarly search engine from the Allen Institute for AI that indexes over 200 million papers across every field of science and uses NLP to surface the most relevant and influential work. Its TLDR feature generates ultra-short, one-sentence summaries of papers, and the Semantic Reader adds inline citation cards and skimming highlights to PDFs. An open API and adaptive Research Feeds let developers and researchers build on the same corpus.
Worth knowing
Built in 2015 by the Allen Institute for AI (AI2), the nonprofit founded by Microsoft co-founder Paul Allen — free, no paywall.
- academic-search
- literature-review
- paper-summaries
- citations
View Zenlytic details AnalyticsPAIDZenlytic
Zenlytic
AI data analyst that investigates business questions against a governed semantic layer.
Zenlytic is a self-serve business intelligence platform whose AI analyst, Zoë, answers natural-language questions by reasoning over a governed semantic layer rather than raw tables, so results map to agreed business definitions. It connects to warehouses like Snowflake, BigQuery, Redshift, and Databricks plus dbt and Looker semantic models, and returns inspectable analyses, visualizations, and reports inside the app or via Slack and Teams. The emphasis is on auditable, defensible answers for non-technical users.
Worth knowing
Started in 2020 as commerce-specific BI before broadening into a general AI data analyst; raised a $9M Series A led by M13 in 2024.
- business-intelligence
- semantic-layer
- text-to-sql
- data-analyst
View Bee details CompanionPAIDBee
Bee
Wrist-worn personal AI that listens to your day and remembers it for you.
Bee is an ambient personal-AI wearable: a $49.99 wristband (the Bee Pioneer) with dual microphones that continuously records and transcribes the conversations around you, then surfaces summaries, to-dos, reminders, and personal insights in its companion app. It connects to email and calendar so it can draft messages and create events from what it hears. The device works without a mandatory subscription; an optional premium tier unlocks advanced search and specialized agents.
Worth knowing
Amazon agreed to acquire Bee in July 2025, signaling its return to AI wearables; the startup had raised about $7M.
- wearable
- ambient-ai
- personal-memory
- voice-recorder
View Surge AI details Data OpsPAIDSurge AI
Surge AI
Premium human data and RLHF for frontier AI labs.
Surge AI provides high-quality human-generated training data and reinforcement learning from human feedback (RLHF) for AI developers. It pairs a large network of expert annotators with a labeling platform and API to produce complex, specialized data — code, math, safety, and domain reasoning — used to train and align frontier models. Reported customers include OpenAI, Anthropic, Google, and Meta.
Worth knowing
Bootstrapped with no outside capital, Surge AI's ~$1.4B revenue in 2025 reportedly surpassed rival Scale AI.
- data-labeling
- rlhf
- training-data
- human-feedback
View SPLX details SecurityPAIDSPLX
Zscaler
Automated AI red teaming, runtime protection, and governance.
SPLX is an AI security platform that runs automated red teaming against LLM apps and AI agents, simulating thousands of adversarial attacks — prompt injection, jailbreaks, data leakage — to surface vulnerabilities. It adds AI asset discovery, system-prompt hardening, runtime protection, and governance across the AI lifecycle, plus Agentic Radar, an open-source scanner for agentic workflows. It targets security teams shipping AI to production.
Worth knowing
Zscaler acquired SPLX in late 2025, folding its automated AI red teaming into the Zero Trust Exchange platform.
- ai-security
- red-teaming
- prompt-injection
- llm-security
- +1
View Kestra details OrchestrationFREEMIUMOpen coreKestra
Kestra Technologies
Open-source orchestration for data, AI, and infrastructure workflows.
Kestra is an open-source orchestration platform for building data, AI, and infrastructure pipelines as declarative YAML workflows. It is event-driven and language-agnostic, running Python, Bash, Node, Go, or containers across 1,500+ plugins, with a web UI for monitoring plus governance features like RBAC and audit logs. It ships as free self-hosted open source alongside paid Cloud and Enterprise editions.
Worth knowing
Raised a $25M Series A in March 2026, bringing its total funding to about $36M.
- orchestration
- data-pipelines
- workflows
- yaml
View Lightly details VisionPAIDLightly
Lightly
Computer-vision data curation, labeling, and model pretraining.
Lightly is a computer-vision data platform that helps teams curate the most informative samples from large image and video datasets using embeddings, active learning, and near-duplicate detection. Its suite spans LightlyStudio (curation and labeling), LightlyTrain (self-supervised pretraining and fine-tuning of vision models), and LightlyEdge (smart data selection on devices). The aim is to cut labeling cost by training on the data that actually improves models.
Worth knowing
Grew out of LightlySSL, the team's open-source self-supervised-learning framework for computer vision.
- computer-vision
- data-curation
- active-learning
- self-supervised
View SuperAnnotate details Data OpsPAIDSuperAnnotate
SuperAnnotate AI
Platform for building multimodal AI datasets and evaluation pipelines.
SuperAnnotate is an enterprise data platform for creating, managing, and evaluating high-quality datasets for AI. It spans annotation across images, video, text, audio, and LiDAR, with AI-assisted labeling, customizable workflows, and an optional managed annotation workforce. Teams use it to build human-in-the-loop data and evaluation pipelines for agentic, multimodal, and frontier AI.
Worth knowing
Its $50M Series B drew NVIDIA, Databricks, and Dell Technologies Capital; the company was founded in Armenia.
- data-labeling
- annotation
- multimodal
- rlhf
- +1
View Good Tape details AudioFREEMIUMGood Tape
Good Tape
Automated AI transcription in 100+ languages.
Good Tape is an AI transcription tool that turns audio and video into accurate, searchable text across 100+ languages with automatic language detection. It adds speaker identification, AI summaries, and smart search, and is built around a privacy-first posture: GDPR compliance, ISO 27001 certification, EU-based servers, AES-256 encryption, and a commitment not to use uploads to train AI. It runs on the web plus iOS and Android apps.
- transcription
- speech-to-text
- privacy
- multilingual
View MindStudio details AutomationFREEMIUMMindStudio
GoMeta
No-code platform to build and deploy AI agents anywhere.
MindStudio is a no-code platform for designing, building, and deploying AI agents. You assemble agents visually and ship them to web apps, browser extensions, email triggers, scheduled automations, APIs, and MCP servers, with optional custom JavaScript or Python for advanced steps. It connects 1,000+ apps and gives access to 200+ AI models through one interface, charging model usage at provider cost with no markup.
Worth knowing
From GoMeta (the team behind the Koji creator platform, ~$36M raised); launched in 2023 as YouAi's MindStudio.
- no-code
- ai-agents
- automation
- agent-builder
View Fellou details AssistantFREEFellou
Fellou AI
Agentic browser that plans and executes web tasks for you.
Fellou is an AI browser that goes beyond chat by embedding agents that autonomously carry out multi-step web work — deep research across many tabs, competitor analysis, form filling, file handling, and cross-app workflows — from a natural-language prompt. It first generates a step-by-step action plan you can review and edit, then executes it while letting you intervene at any step. It runs as a downloadable desktop browser and can analyze local files dragged into the interface.
Worth knowing
Markets itself as the first 'agentic browser'; later shipped Fellou CE, billed as a spatial (Z-axis) edition with local-first execution.
- agentic-browser
- web-automation
- ai-browser
- research
View Opal details AutomationFREEOpal
Google
Build and share AI mini-apps from a plain-language description.
Opal is an experimental Google Labs tool for building AI mini-apps without code. You describe a task in natural language and Opal generates a workflow that chains prompts, models, and tools, which you can refine in a visual node editor and share with others via a link. It targets marketers, analysts, and other non-engineers who want to prototype and ship small AI-powered tools quickly.
Worth knowing
Built by Google Labs; launched July 2025 as a US-only public beta, then expanded to 15+ more countries.
- no-code
- workflow-builder
- ai-apps
- google-labs
View Agno details OrchestrationFREEOSSAgno
Agno
High-performance Python framework for multi-agent systems.
Agno is an open-source Python framework for building multi-agent systems with memory, knowledge, tools, and reasoning. Agents are fast to instantiate and can be composed into teams, and the companion AgentOS runtime serves them in production as a FastAPI app with a control plane.
Worth knowing
Rebranded from Phidata in early 2025; its 2.0 release added AgentOS, a FastAPI runtime for serving agents in production.
- agents
- multi-agent
- framework
- agentos
- +1
View DSPy details OrchestrationFREEOSSDSPy
Stanford NLP
Program — don't prompt — your language models.
DSPy is an open-source Python framework for building LLM applications by writing modular code instead of brittle prompt strings. You declare input/output signatures and compose modules, then DSPy compiles and optimizes the underlying prompts — and can even tune model weights — for classifiers, RAG pipelines, and agent loops.
Worth knowing
Created in the Stanford NLP group; the name stands for "Declarative Self-improving Python."
- llm-framework
- prompt-optimization
- rag
- agents
- +1
View Fellow details MeetingFREEMIUMFellow
Fellow
AI meeting assistant that records, transcribes, and summarizes.
Fellow is an AI meeting assistant and notetaker that transcribes, summarizes, and extracts action items from calls with human-level accuracy. It offers both bot-based and botless recording, works across Zoom, Google Meet, and Teams, and its Ask Fellow agent answers questions across past meetings.
Worth knowing
Began as a meeting-agenda and management tool on fellow.app, then repositioned around AI notetaking and moved to the fellow.ai domain.
- meetings
- notetaker
- transcription
- summaries
View Toolhouse details MCPFREEMIUMToolhouse
Toolhouse
Build and deploy AI agents as APIs, with MCP tools built in.
Toolhouse is a backend-as-a-service for AI agents: define an agent in plain language or code and deploy it as an API in one command. Agents connect automatically to the Toolhouse MCP server, which provides RAG, memory, code execution, browser use, and 1,000+ tool integrations over the Model Context Protocol.
Worth knowing
Its free Sandbox tier includes free OpenAI model usage, so you can build and launch an agent without bringing your own API key.
- mcp
- ai-agents
- tools
- rag
- +1
View Wordly details TranslationPAIDWordly
Wordly
Real-time AI translation and captions for meetings and events.
Wordly delivers real-time AI translation, live captions, transcripts, and summaries for meetings and events across dozens of languages — no special equipment or human interpreters required. It works with Zoom, Teams, Google Meet, Webex, and in-person events, and attendees join translated audio or captions from a browser or the mobile app.
Worth knowing
Has powered over 1 billion minutes of live AI translation for 6M users across 120 countries, with $200M+ saved versus human interpreters.
- translation
- captions
- interpretation
- events
- +1
View Freeplay details EvalPAIDFreeplay
Freeplay
Eval and observability ops platform for AI product teams.
Freeplay is an LLM evaluation and observability platform that unifies prompt management, batch evals, experiments, and production monitoring in one workflow. Built for cross-functional teams, it lets engineers, PMs, and domain experts review the same traces, run model-graded and code-based evals, and align auto-evaluators with human labels before shipping.
Worth knowing
Founded in 2022 by two former Twitter developer-platform leaders; raised a $5.6M round led by Renegade Partners in June 2025.
- llm-eval
- observability
- prompt-management
- experiments
View Globe Explorer details SearchFREEGlobe Explorer
Globe Engineer
A discovery engine — a Wikipedia page for anything.
Globe Explorer is an AI discovery engine that turns any query into a single structured, visual page instead of a ranked list of links. It uses LLMs to break a topic into a hierarchy — broad overview down through subtopics — that you can explore, expand and share. It's free to use and aimed at learning and research rather than precise factual lookups.
Worth knowing
Went viral on X in 2024 as a free ‘discovery engine’ from Globe Engineer, drawing comparisons to a self-assembling Wikipedia.
- ai-search
- discovery
- knowledge-map
- research
View Novelcrafter details WritingPAIDNovelcrafter
Novelcrafter
Plan, write and organize your novel with bring-your-own-key AI.
Novelcrafter is a browser-based platform for fiction and non-fiction authors that pairs a full manuscript editor with a worldbuilding wiki called the Codex for characters, places and lore. AI features — scene generation, summaries, character extraction and beat-to-scene drafting — run through your own provider key, so you choose the model and pay the API rates directly. Plans start at $4/month after a free trial.
Worth knowing
Bootstrapped and built by writers with no venture funding; AI is strictly bring-your-own-key, so the app never marks up model usage.
- fiction-writing
- novel
- worldbuilding
- byo-key
- +1
View Onlook details DesignFREEMIUMOpen coreOnlook
Onlook
The Cursor for designers — edit React apps visually in real code.
Onlook is an open-source visual editor that lets designers and developers build and edit Next.js + Tailwind apps directly on an infinite canvas while the actual codebase stays the source of truth. You drag, style and tweak live React components and Onlook writes the corresponding code, with AI assistance for larger changes. It can be self-hosted for free, with a managed cloud version for teams.
Worth knowing
Open-source (Apache-2.0) and a Y Combinator W25 startup; its visual-editor repo trended #1 on GitHub and has 25k+ stars.
- design-to-code
- react
- visual-editor
- open-source
- +1
View Soundful details MusicFREEMIUMSoundful
Soundful
AI music generator for unique, royalty-free tracks.
Soundful is an AI music platform that generates original, royalty-free instrumental tracks from a chosen genre and template, exporting MP3, WAV and separated stems with MIDI. Its models are built with real producers on owned and licensed material rather than scraped recordings, so finished tracks are clear to monetize. A free Standard tier covers personal use, with paid plans unlocking commercial licenses and stems.
Worth knowing
Founded in 2021 by composer Diaa El All; its $3.8M seed round drew leaders from Universal Music Group, Disney, Microsoft and Beatport.
- music-generation
- royalty-free
- text-to-music
- content-creators
View Sema4.ai details AutomationPAIDSema4.ai
Sema4.ai
Enterprise platform to build and run AI agents for knowledge work.
Sema4.ai is a full-stack enterprise platform for building, running, and operating AI agents that automate complex back-office knowledge work across finance, procurement, and supply chain. It pairs large language models with deterministic, auditable actions so agents can handle tasks like invoice processing and regulatory compliance at scale. The platform runs natively on Snowflake's Data Cloud and grew out of the team behind open-source automation pioneer Robocorp. The Atlanta-based company came out of stealth in 2024.
Worth knowing
Came out of stealth in 2024 backed by Benchmark and Mayfield, then acquired open-source automation pioneer Robocorp.
- ai-agents
- enterprise-automation
- snowflake
- back-office