Best size chart builder for bootstrapped startups

There are roughly 40-60 dedicated size chart tools in the market, but most are either enterprise-grade with $500+/month pricing or bare-bones free options that don't integrate well with Shopify or WooCommerce. The core pain point isn't creating charts—it's that bootstrapped shippers need something that works out-of-the-box without hiring a dev, costs under $50/month, and actually reduces returns through comparison features (side-by-side measurements, customer reviews by size, brand-specific guidance). Most existing tools fail because they're either too complex (overstuffed with features shippers don't need) or too simple (static images that don't drive conversions). The real gap is a lightweight, plug-and-play solution that includes: automatic brand syncing, customer feedback loops ("this ran small"), mobile-first design, and A/B testing to show which format actually kills returns. A new entrant should obsess over sub-$30/month pricing with zero setup friction—template galleries for common categories (apparel, shoes, accessories) so founders ship in minutes, not hours.