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 + Kimi
- Images/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 Plus
- Design ($10): MidJourney
- Audio ($10): Suno Pro + ElevenLabs
- Coding ($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.