Chapper: Native iOS Client for LM Studio, Ollama, and OpenAI-Compatible Local Models

Chapper is a native SwiftUI iOS client for connecting to local AI models running on LM Studio, Ollama, and any OpenAI-compatible server. The app runs entirely on-device with no cloud requirements, web views, or mandatory accounts.

Core Features

• Real-time token streaming with live inference speed display
• Full sampling controls: temperature, top-p, top-k, min-p, TFS-Z, repeat/presence/frequency penalty
• Structured output/JSON schema mode
• Markdown rendering with syntax-highlighted code blocks

Reasoning Model Support

• Collapsible thought process panel inline above each response
• Works with Qwen3, DeepSeek-R1, and any model using <think> tags
• Custom <think> tag parser for reasoning model output

Model Management

• In-app model management: browse, load, configure context length
• Flash attention support
• GPU KV-cache offload

Conversation Features

• Personas with persistent system prompts per chat
• Full-text search across all conversations + pinned chats
• Memory system that injects long-term context automatically
• Scratchpad for working notes while chatting

Output Options

• Export in 7 formats: PDF, HTML, Markdown, JSON, CSV, XML, TXT
• TTS in three modes: native iOS voices, local on-device Kokoro model (experimental), or custom TTS server
• Background playback support

Technical Implementation

• Native async streaming over SSE
• MCP tool integration for web search, file access, URL fetching
• iCloud sync (optional)
• On-device analytics dashboard
• 12 language support
• Custom haptics with toggle option

Pricing & Availability

Free + Pro model with one-time purchase, no subscription. Core chat is free. Pro unlocks advanced sampling, unlimited history, all export formats, custom icons, and unlimited personas. Works on iPhone and iPad.