As of June 2025, AI has evolved into a “two-layer ecosystem” of Applications and Models. The upper layer offers AI tools that anyone can use out of the box, while the lower layer provides open‑source foundation models that drive innovation. This article organizes 8 major categories and 50+ top AI applications and core open‑source models — covering general chat, image generation, video creation, research tools, and more — highlighting free/paid options, key features, and access points, helping you unlock AI superpowers with a single click.
🧰 Application Layer: AI Tools You Can Use Right Now
🤖 1. General AI Assistants — The 24/7 Brain
Tool Highlights Free Plan Pricing ChatGPT Chat, coding, translation, drawing/speech — the all-round AI standard GPT‑3.5 Free GPT‑4o/Plus $20/month Google Gemini Flagship multi‑modal model, long context (1–2M tokens), multi‑turn chat Gemini 1.5 Pro Free Gemini Advanced $19.99/month Claude Premium reasoning, long context (200k+ tokens), ideal for docs & creative work Generous Free Plan Pro $20/month Microsoft Copilot ✅ Totally free, GPT‑4o integrated, real‑time search and vision ✅ Totally Free — DeepSeek ✅ Strong Chinese reasoning, paper review, code generation ✅ Totally Free — Poe by Quora Multiple models (GPT‑4, Claude 3.5, Llama 3, etc.) in one app Free daily quota $19.99/month subscription
🎨 2. AI Image Creation — Everyone Is a Designer
Tool Highlights Free Plan Pricing Bing Image Creator DALL·E 3 powered, supports Chinese prompts, very low barrier ✅ Totally Free — MidJourney The king of concept design and illustration, highly stylized results — From $10/month Leonardo AI Game assets, commercial design, rich presets, custom model training 150 daily points $12–30/month Adobe Firefly Adobe-trained, commercially safe AI generation, seamless integration Free points for Adobe subs Part of Adobe Creative Cloud ($20.99+)
✍️ 3. AI Writing Assistance — All‑in‑One Rewriting & Polishing
Tool Highlights Free Plan Pricing Kimi Breaks long text barriers (2M chars), ideal for long‑form reading & generation ✅ Totally Free — Grammarly Leading grammar, style, and AI-assisted rewrites Basic Free Premium $12/month Xunfei Huiwen Starfire MAX + DeepSeek collaboration, multi‑scenario text help ✅ Totally Free — Volcano Writing Polishing for Chinese/English, trend‑aware articles ✅ Totally Free — Notion AI Integrated AI within Notion for drafting, summarization, and brainstorming Free trials available $8–10/user per month BiLing AI Plagiarism & rework tool, ideal for academic rewrites Limited trials ¥23/month (~$3.20)
🎥 4. AI Video and Multimodal Creation — AI Dream Machines
Tool Highlights Free Plan Pricing Sora (OpenAI) Text‑to‑video generation (1‑min), advanced physics & motion understanding (Product page) — Google Veo High‑fidelity video generation and long shots with cinematic precision (Product page) Expected in Gemini Advanced Kling AI Developed by Kuaishou, advanced video generation with realistic dynamics 66 daily credits Premium options available Jemeng AI By ByteDance, text‑to‑image and text‑to‑video generation (anime, realistic) Daily free points Subscription available Hailuo AI (MiniMax) High‑quality AI video generation + chat + document AI in one Free shell (points) upon login Premium subscription (¥10788/year) Runway All‑in‑one video toolbox for generation, motion tracking, masking, and more Limited Free Export Pro from $12/month Pika Labs 3D video generation and editing ✅ Free —
🔍 5. AI for Research and Retrieval — Academic Must‑Haves
Tool Highlights Free Plan Pricing Perplexity Chat‑based search with clear citations and academic focus ✅ Free Plan Pro $148.8/year Elicit Automated literature review and summarization ✅ Totally Free — Consensus AI‑powered academic search engine extracting direct paper answers ✅ Free Plan Premium available Nami AI Multimodal search and automated PPT generation ✅ Limited Free Premium available
⚡️ 6. AI for Office & Productivity — The Anti‑Burnout Toolkit
Tool Highlights Free Plan Pricing Tome AI‑driven slide generation and structured presentations ✅ Free Plan Premium available Gamma AI site‑styled presentation and doc generation, sleek design Free with watermark Pro $16/month ClickUp AI AI for task automation, content generation, and collaboration Part of paid plans Add‑on $5/user/month Tencent Yuanbao Deep WeChat office integration for document and data processing ✅ Sonnet Free Premium available Microsoft Copilot for 365 Integrated across MS Office, enterprise‑level automation powerhouse (Product page) $30/user per month (business)
🎵 7. AI Audio and Music — Everyone’s a Composer
Tool Highlights Free Plan Pricing Suno Text‑to‑song generation, vocals and composition Daily free points Pro from $10/month ElevenLabs Industry‑leading voice generation and cloning Free character quota $5+/month
💻 8. AI Coding Assistants — Your Pair Programmer
Tool Highlights Free Plan Pricing GitHub Copilot The industry’s best coding assistant, deep IDE integration Free for students & teachers $10/month (Individual), $19/user (Business) Amazon CodeWhisperer AWS coding assistant with security scans ✅ Free for individuals —
⚡ Model Layer: The Foundation of AI Innovation
💡 9. Open‑Source Large Models (For Developers and Tech Enthusiasts)
Model Developer Highlights Llama Series Meta The best‑known open‑source LLM series, extensive ecosystem. Mistral Series Mistral AI Europe’s top LLM series, highly efficient, strong in smaller sizes. Qwen Series Alibaba Cloud Strong long‑context and multilingual capabilities. DeepSeek-Coder/LLM DeepSeek AI Open‑source powerhouse for coding and general tasks. abab Series MiniMax High‑quality Chinese open‑source LLM series. ChatGLM Series Zhipu AI Developed by Tsinghua, highly popular in Chinese AI ecosystem. Stable Diffusion Stability AI Cornerstone for open‑source image generation, highly customizable.
💰 10. The Smart Cost‑Saving Combos
🥇 Free Power Combo (For Most Users)
General/Search/Writing : Microsoft Copilot + Claude + KimiImages/Videos : Bing Image Creator + Jemeng + Kling (daily free usage)Office/Research : Notion AI (free quota) + Gamma + Perplexity
🥈 Cost‑Effective Combo (For Creators)
Core Model ($20) : Claude Pro or ChatGPT PlusDesign ($10) : MidJourneyAudio ($10) : Suno Pro + ElevenLabsCoding ($10) : GitHub Copilot
🥉 DIY Geek Combo (For Technical Players)
Local LLM : Llama 3 / Qwen 2 / Mistral (choose one)Local Images : Stable Diffusion (ComfyUI / Automatic1111)UI Framework : Ollama + Open WebUI
⚡️ 11. Final Advice & Summary
The AI Dual‑Layer Architecture
In 2025, you must understand AI’s dual‑layer structure:
Application Layer : Ready‑to‑use tools for everyday productivity.Model Layer : Technical foundations for innovation, granting developers and enthusiasts maximum creative freedom.
Final Thoughts
✅ Free Tools Are Stronger Than Ever — Thanks to platforms like DeepSeek, Microsoft Copilot, Claude, and Kimi, 95% of daily AI needs can be met for free.
💳 Premium Tools Solve Specific Challenges — ChatGPT Plus, MidJourney, GitHub Copilot, and others remain top picks for professionals.
🌐 Open‑Source Models Will Shape the Future — From DeepSeek and MiniMax to Llama, Qwen, and Stable Diffusion, open‑source AI grants developers ultimate control and sparks unprecedented innovation.
