Vector Space AI vs Arbiter
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Vector Space AI
This app offers a fast, private AI companion that runs locally on your device, providing instant responses for writing, brainstorming, and coding. It also allows seamless switching to cloud-based AI for more advanced queries.
- Runs locally on device
- Optional ChatGPT API connection
- Modern and clean interface
- Instant response times
- Complete user data privacy
- Seamless mode switching
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Chat with FREE, FAST and POWERFUL AI that runs LOCALLY on your iPhone Meet your new AI companion that’s always available — no cloud, no lag, just pure speed. Our advanced local AI engine runs directly on your iPhone, giving you instant responses, full privacy, and offline intelligence. Whether you’re writing, brainstorming, translating, or coding — everything happens right on your device. And when you want to connect to the cloud, simply switch to ChatGPT API mode for even more powerful, up-to-date answers. Key Features: - Runs Locally — Experience lightning-fast chat without internet or server delay. - Optionally, Connect to by ChatGPT API — Access the world’s smartest AI whenever you want. - Beautiful Modern Design — A clean, elegant interface built for clarity and focus. - Instant Responses — No waiting. No spinning wheels. Just smooth conversation. - Completely Private — Your data stays on your device. Nothing leaves your phone. - Seamless Mode Switching — Toggle between local AI and ChatGPT in one tap. Why You’ll Love It: Because it’s your AI — fast, powerful, private, and beautifully crafted. Talk, create, think, and explore ideas anywhere — even offline. Download now and experience the future of AI — FAST. PRIVATE. BEAUTIFUL. LOCAL.
Arbiter
This privacy-focused AI assistant operates entirely on your device, offering offline functionality. Choose from various open-source models to suit your needs, with all conversations securely stored locally. It's ideal for brainstorming, proofreading, and exploring AI capabilities without data collection.
- On-device AI processing
- Offline model execution
- Document summarization
- Privacy-focused design
- Multiple AI model selection
- Local data storage
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Arbiter is a privacy-first offline AI assistant that runs on your device. Choose from lightweight open-source models like Gemma, Llama, DeepSeek, Qwen, and Mistral, or connect to larger models running on your PC or Mac over your local network. You can also connect to Arbiter for Mac when it is serving a local model on your network. There are no accounts, servers, or data collection. All your conversations are stored securely on your device, under your control. Key Features: - On-Device AI: Download and run models locally on your iPhone - Apple Intelligence Support: Use Apple’s on-device Foundation Model on supported devices without downloading another model - Local Image Generation: Create images directly on your device with Stable Diffusion - Local Network Models: Connect to more powerful models running on your PC or Mac through tools like LM Studio, Ollama, or Arbiter for Mac - Visual AI Support: Upload images or take photos in-app to use with MLX-powered visual models - Document & File Uploads: Summarize files and extract key insights - Expanded File Support: Work with DOCX, RTF, HTML, Markdown, CSV, JSON, code, PDF, and text files - Bring Your Own Model: Search Hugging Face, download compatible models, or import supported GGUF files and MLX folders already on your device - MCP Tools: Connect to compatible MCP servers, review tool arguments, and run tools when needed - Optional Web Search: Access up-to-date information when needed, while keeping your core experience private and local - Smart Chat Suggestions: Context-aware suggestions tailored to your selected model and role - Personalization: Customize system prompts and model settings for a more tailored experience - Advanced Model Controls: Adjust context size, maximum response length, temperature, Top-P, and Top-K - Local Model Benchmarking: Measure model quality, speed, response time, and memory use directly on your device - Privacy by Design: Your conversations and data never leave your device unless you choose to enable web search or connect to a local network model - Model Flexibility: Choose from multiple open-source AI models to balance speed, accuracy, and memory use - Improved Reliability: Smarter context handling and enhanced error management for a more stable experience - No Hidden Costs: Avoid expensive cloud fees with local and local-network processing Whether you want to brainstorm, code, proofread text, analyze images, summarize files, search the web, or experiment with the latest open-source AI, Arbiter makes advanced AI models accessible while keeping your data in your hands. Device Requirements: For smooth on-device performance, Arbiter is recommended for iPhone 13 Pro or later, or devices with at least 6GB RAM. Older devices may experience memory issues or crashes.
Screenshots
Verdict
The clearest difference is in-app purchases: Vector Space AI at none against Arbiter's 4. Vector Space AI also leads on update cadence (every 4 days vs fortnightly). On price, review sentiment, ads and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Arbiter sells 4 one-off in-app purchases. Vector Space AI asks for nothing beyond the download.
Vector Space AI ships an update every 4 days, Arbiter fortnightly. Both last shipped on October 8, 2026.
| Parameter | Vector Space AI | Arbiter |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.9 (16 ratings) — better |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | — | 16 — better |
| Update frequency | Every 4 days — better | Fortnightly |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, Mac |
| Requires iOS | 18.0 — better | 18.4 |
| Further details — not scored | ||
| Size | 34 MB | 40 MB |
| Age rating | 4+ | 4+ |
| Developer | Voila Tech K.K | Jordan Stone |
Customer experience
Vector Space AI
Arbiter
In-app purchases
Vector Space AI
No in-app purchases
Arbiter
- Small Tip$1.99
- Medium Tip$4.99
- Large Tip$9.99
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- Extra Large Tip$19.99









