I’m building SpareCent, a micro-saving app that rounds every purchase up to the next whole number and sweeps the spare change into a secure stash. The experience I’m after is frictionless: a user links their card or bank account, we monitor transactions in real time, calculate the difference, and move that amount automatically. Beyond the core round-up engine I need three companion features baked in from day one: • a goal tracker where users name goals, set target amounts and deadlines, and watch the progress bar inch forward; • smart alerts and notifications that congratulate, remind, or flag unusual activity; • lightweight spending insights that summarise categories, totals, and simple trends so users understand where their money goes. Security and UX must be top-tier. Think bank-grade encryption, clear consent screens, and an interface that feels perfectly native on both iOS and Android—React Native, Flutter, or any cross-platform stack that keeps performance snappy works for me. Please recommend an open-banking aggregator (Plaid, Teller, Salt Edge, etc.) and outline how you’d minimise ongoing API costs while still giving users near-instant feedback. Acceptance criteria • Round-up transfers post successfully in a sandbox against at least one open-banking provider. • Users can create, edit, and delete multiple savings goals and assign round-ups to them. • Push and in-app notifications fire based on rules I’ll supply. • Spending insights dashboard displays category totals and a 30-day trendline. • All source code, build instructions, and a concise technical doc handed over at sign-off. If you’ve shipped fintech products before—especially anything that touches open-banking APIs—I’d love to see your work and hear your approach.