diff --git a/docs/LOCALIZATION_IMPLEMENTATION_PLAN.md b/docs/LOCALIZATION_IMPLEMENTATION_PLAN.md
index 6138b55..6a32d19 100644
--- a/docs/LOCALIZATION_IMPLEMENTATION_PLAN.md
+++ b/docs/LOCALIZATION_IMPLEMENTATION_PLAN.md
@@ -287,34 +287,43 @@ Features:
 
 ---
 
-## Phase 6: Onboarding Flow Integration ❌ TODO
+## Phase 6: Onboarding Flow Integration ✅ COMPLETED
 
-### 6.1 Update Onboarding Page
-**File**: `app/(auth)/onboarding/page.tsx` (MODIFY)
+### 6.1 Update Onboarding Page ✅
+**File**: `app/(auth)/onboarding/page.tsx` (COMPLETED)
 
-Add new steps:
-1. Language selection (Step 2)
-2. Measurement unit selection (Step 3)
+✅ Implemented 5-step flow:
+1. Welcome screen
+2. Language selection (Step 1)
+3. Measurement unit selection (Step 2)
+4. Add child (Step 3)
+5. Complete (Step 4)
 
-### 6.2 Onboarding Language Step Component
-**File**: `components/onboarding/LanguageStep.tsx` (NEW)
+### 6.2 Onboarding Language Step ✅
+**Implementation**: Integrated directly in onboarding page
 
-- Large, visual language selector
-- Show language names in native script
-- Save to Redux state
-- Update i18n immediately
+- ✅ Visual language selector with all 7 languages
+- ✅ Shows language names in native script (English, Español, Français, Português, 中文, Deutsch, Italiano)
+- ✅ Saves preference to backend via `usersApi.updatePreferences`
+- ✅ Updates i18n immediately via `useLocale` hook
+- ✅ Beautiful card-based selection UI with radio buttons
 
-### 6.3 Onboarding Measurement Step Component
-**File**: `components/onboarding/MeasurementStep.tsx` (NEW)
+### 6.3 Onboarding Measurement Step ✅
+**Implementation**: Integrated directly in onboarding page
 
-- Visual metric/imperial selector
-- Show examples (ml vs oz, cm vs in)
-- Save to Redux state
+- ✅ Visual metric/imperial selector
+- ✅ Shows examples (kg, cm, °C, ml vs lb, in, °F, oz)
+- ✅ Saves preference to backend and localStorage
+- ✅ Updates measurement system via `useLocale` hook
+- ✅ Card-based selection UI for better UX
 
-### 6.4 Update Onboarding API Call
-**File**: `app/(auth)/onboarding/page.tsx` (MODIFY)
+### 6.4 API Integration ✅
+**File**: `app/(auth)/onboarding/page.tsx` (COMPLETED)
 
-Include language and measurementUnit in profile update call.
+- ✅ Language saved to backend via `usersApi.updatePreferences({ language })`
+- ✅ Measurement unit saved via `usersApi.updatePreferences({ measurementUnit })`
+- ✅ User profile refreshed after each preference update
+- ✅ Error handling with graceful fallback
 
 ---
 
@@ -747,12 +756,13 @@ Document language and measurement preferences in user guide
 
 ### 🟢 Low Priority (Nice to Have)
 
-3. **Onboarding Flow** (Phase 6)
+3. ✅ **Onboarding Flow** (Phase 6) - COMPLETED
    - ✅ Onboarding translations complete (all 7 languages)
-   - ⏳ Add language selection step UI
-   - ⏳ Add measurement unit selection step UI
-   - ⏳ Save preferences during onboarding
-   - **Estimated Effort**: 2-3 hours
+   - ✅ Language selection step UI implemented
+   - ✅ Measurement unit selection step UI implemented
+   - ✅ Preferences saved to backend during onboarding
+   - ✅ 5-step onboarding flow: Welcome → Language → Measurements → Add Child → Complete
+   - **Status**: FULLY IMPLEMENTED
 
 ### 🟢 Low Priority (Future Enhancements)
 
@@ -778,28 +788,29 @@ Document language and measurement preferences in user guide
 
 ### 📊 Progress Tracking - UPDATED October 3, 2025
 
-**Completed**: 13 phases (1-5, 7-9, 12, 13.2, and partial 6, 10-11)
+**Completed**: 14 phases (1-9, 12, 13.2, and partial 10-11)
 **In Progress**: 0 phases
-**Remaining**: 3 major phases (6, 10, 11, 14)
+**Remaining**: 2 major phases (10, 11, 14)
 
-**Overall Completion**: ~92% (core functionality + all translations + unit conversions)
+**Overall Completion**: ~95% (core functionality + all translations + unit conversions + onboarding)
 
 **🎉 Major Milestones Achieved**: 
 - ✅ All 77 translation files completed across 7 languages
 - ✅ All main pages fully localized and integrated
 - ✅ All tracking pages with unit conversions COMPLETED
 - ✅ UnitInput component fully implemented and integrated
+- ✅ **Onboarding flow with language & measurement selection COMPLETED**
 - ✅ Frontend card symmetry completed for professional appearance
 - ✅ i18n configuration fixed and all languages loading correctly
 
 **Estimated Time to Full Completion**:
-- Medium Priority (Phase 6 - Onboarding, Phase 10-11 - Date/Number formatting): 4-6 hours
+- Medium Priority (Phase 10-11 - Date/Number formatting refinement): 2-4 hours
 - Low Priority (Phase 14 - Testing, Phase 15 - Documentation): 3-5 hours
-- **Total Remaining**: 7-11 hours (1 day)
+- **Total Remaining**: 5-9 hours (0.5-1 day)
 
 ---
 
-**Total Project Effort**: 3.5 days (completed) + 1 day (remaining) = 4.5 days
+**Total Project Effort**: 4 days (completed) + 0.5-1 day (remaining) = 4.5-5 days
 **Complexity**: Medium
 **Priority**: HIGH (Pre-Launch)
-**Current Status**: Core functionality 92% complete, translations 100% complete, unit conversions 100% complete, **PRODUCTION-READY**
+**Current Status**: Core functionality 95% complete, translations 100% complete, unit conversions 100% complete, onboarding 100% complete, **PRODUCTION-READY**
diff --git a/maternal-web/components/layouts/TabBar/TabBar.tsx b/maternal-web/components/layouts/TabBar/TabBar.tsx
index 2146803..a898560 100644
--- a/maternal-web/components/layouts/TabBar/TabBar.tsx
+++ b/maternal-web/components/layouts/TabBar/TabBar.tsx
@@ -7,7 +7,7 @@ import {
   Home,
   Timeline,
   Insights,
-  History,
+  Chat,
   Mic,
 } from '@mui/icons-material';
 import { useTranslation } from '@/hooks/useTranslation';
@@ -23,7 +23,7 @@ export const TabBar = () => {
     { label: t('navigation.track'), icon: <Timeline />, value: '/track' },
     { label: '', icon: null, value: 'voice' }, // Placeholder for center button
     { label: t('navigation.insights'), icon: <Insights />, value: '/insights' },
-    { label: t('navigation.history'), icon: <History />, value: '/history' },
+    { label: t('navigation.aiChat'), icon: <Chat />, value: '/ai-assistant' },
   ];
 
   return (