Smart Shopping iOS App Plan

I have an idea for an iPhone app that lets users simply speak a grocery list, parses every item with Whisper-style speech recognition, looks up prices across participating retailers, and highlights the cheapest practical way to buy everything. What I need from you is a concise yet technically thorough software-development plan that turns this concept into an executable roadmap. Core scope • Speech input: assume use of Whisper (or an equally accurate on-device/edge model) to turn natural speech into text. • List structuring: the plan must cover how we map that raw text into standardised grocery product names and quantities. • Price engine: devise a flow for querying multiple retailer catalogues and promotions, then ranking the results on final basket cost. • Brand handling: include a mechanism for users to express brand preferences and, by default, have the algorithm favour store brands over national or organic alternatives while still allowing flexibility. • iOS-first: lay out the recommended architecture (Swift / SwiftUI, Combine, Core Data or CloudKit, etc.) along with any backend or third-party services you feel are unavoidable. Deliverables 1. A written architecture document (1-2 pages per module) covering data models, service layers, and key classes. 2. Sequence diagrams or flowcharts that show how speech input becomes a priced shopping basket. 3. A milestone schedule with rough time estimates and logical dependencies. 4. Risk list with mitigation strategies, especially around catalogue data quality and speech-to-product accuracy. 5. Toolchain recommendations (CI/CD, testing frameworks, analytics, crash reporting). Acceptance criteria • All five deliverables are returned in a single, well-organised PDF or shared document. • Each module description includes at least one alternative approach with pros/cons. • Brand-preference logic explicitly demonstrates how store brands are prioritised. • No section exceeds three concise paragraphs unless absolutely necessary. If the outline looks feasible, I will green-light the next phase—detailed UX wireframes followed by development. I look forward to seeing how you’d bring this smart shopping assistant to life.