Building TotTrack: A Child Development App From Scratch

TotTrack started with a simple question: why is it so hard for parents to track their child's development when the NHS sends you the form a month before the reviews, or if you really can't wait then an expensive trip to a private paediatrician?

The answer was to build something purpose-made. A web and mobile app that lets parents log milestones, run activities, generate powerful development reports using AI, and share progress with family, nursery or medical practitioners — all in one place. Here's how we built it.

The Problem

Parents of children aged 1–5 are constantly wondering: is my child on track? Are they hitting their milestones? What activities should I be doing with them? Worse, they believe something may be amiss and have no way of checking.

The existing options weren't great:

• Generic milestone checklists — static PDFs that don't adapt to your child
• Baby apps — focused on feeding, sleeping and nappy tracking, not development
• Paediatrician visits — expensive, infrequent, and often just a brief check

We wanted something that combined milestone tracking with actionable guidance — and used AI to give parents genuinely personalised insights that feed back into recommendations for further development.

What We Built

Milestone Tracking

Parents log milestones as they happen or retrospectively — first steps, first words, recognising colours, counting to ten. Each milestone can include photos and notes. The app tracks these against age-appropriate developmental benchmarks, so parents can see at a glance where their child is thriving and where they might need a bit more support.

54 Developmental Activities

The app includes 54 structured activities across 7 developmental categories: cognitive, creative, language, motor, sensory, social, and custom activities parents can create themselves. Each activity is age-appropriate and designed to be done at home with everyday items.

AI-Powered Development Reports

This is where it gets interesting. Using the milestone and activity data a parent has logged, TotTrack generates comprehensive development analysis reports powered by Claude. These aren't generic summaries — they're personalised assessments based on what the parent has actually recorded.

The reports cover each developmental area, highlight strengths and areas for attention, and are downloadable as PDFs — useful for sharing with nurseries, health visitors, or family members.

Personal Development Plans

After each analysis report, the system automatically generates a development plan. This recommends specific in-app activities the parent can do, plus external activities and resources. The plan is tailored to the child's current stage and the areas flagged in their report.

Family Sharing

Parents can invite partners, grandparents, or carers to view their child's profile. Role-based access means you can control who sees what — full editing access for co-parents, read-only for grandparents who just want to see the latest photos and milestones.

The Tech Stack

We chose a modern stack that prioritised speed of development and cross-platform reach:

• React + Vite + TypeScript for the web app — fast build times, type safety, excellent developer experience
• React Native + Expo for iOS — shared component logic with the web app
• Tailwind CSS for styling — rapid UI development without fighting custom CSS
• Drizzle ORM + Neon PostgreSQL for the database — serverless Postgres with type-safe queries
• Anthropic's Claude for AI reports and development plans — the depth of analysis far exceeded what we could get from other models
• Stripe + Apple IAP for billing — 14-day free trial, then subscription

Hard Problems We Solved

AI Report Reliability

When you're generating multi-page development reports with AI, reliability is everything. Parents are reading these reports to understand their child's development — they need to be accurate and well-structured every time.

We built a robust pipeline: structured prompts with the child's specific data, max token limits to prevent runaway responses, JSON sanitisation for development plans, and an AI-powered repair step that catches and fixes malformed output before it reaches the parent. The result is reliable, consistent reports even with edge cases.

Cross-Platform Without the Pain

Running a React web app and a React Native iOS app from the same codebase sounds great in theory. In practice, it means carefully managing which components are shared and which need platform-specific implementations. We ended up with a pragmatic split: shared business logic and API layer, with platform-specific UI where the experience needed to differ.

Background Processing

AI report generation is an intense process and takes a few minutes. You can't make a parent stare at a spinner for that long. We built a background job system that kicks off report generation asynchronously, tracks progress, and notifies the parent when their report is ready. If the server restarts mid-generation, stale jobs are automatically detected and marked as failed so parents aren't left waiting forever.

What We Learned

A few takeaways from building TotTrack that apply to any custom app project:

• Start with the core loop. For TotTrack, that's: log a milestone → run an activity → generate a report. Everything else is secondary. We shipped with this loop working end-to-end before adding family sharing, billing, or development plans.
• AI features need guardrails. LLMs are powerful but unpredictable. Every AI-generated output needs validation, error handling, and a fallback. We invested heavily in this and it paid off.
• Cut scope ruthlessly. We originally included emotion tracking, mood logging, nutrition tracking, and sleep tracking. All removed. They diluted the core value proposition and added maintenance overhead without proportional user value.
• Error monitoring from day one. We built a self-hosted error logging system that captures server errors, client errors, and background job failures. A cron job emails summaries every two hours. This caught issues in production that would have taken days to surface otherwise.

The Result

TotTrack is live at tottrack.co — a fully functional child development tracker that parents use daily. It demonstrates what's possible when you build custom software with modern tools: an app that would have taken a large team months to build, delivered by a small team using AI-assisted development.

More importantly, it shows the kind of application we build at SH Applications. Not templates. Not no-code prototypes. Real, production-grade software designed around a specific problem, built to last.