Anyone who's travelled knows the airport ritual: land in a new country, hunt for a SIM kiosk, hand over your passport, swap the tiny card, and hope you didn't just lose your home number for the trip. Seyyah Mobile was built to delete that whole routine. You buy connectivity from your phone, and you're online — no kiosk, no roaming bill, no fiddly card.
The product is an eSIM platform covering 165+ countries, so the first design problem was making a genuinely global catalogue feel small and personal. Nobody wants to scroll a list of every country on earth. We focused the flow on the one thing the traveller actually wants in that moment: pick where you're going, see a clear plan, pay, done.
Under the hood, an eSIM app is really a coordination problem. There's the purchase, the eSIM provisioning, the payment, and the ongoing top-ups when someone's data runs low mid-trip. We wired these together through clean API integrations so the app stays simple on the surface while the moving parts stay reliable underneath.
Payments needed special care. People buy these on the move, sometimes on a patchy connection in an unfamiliar place, and a confusing checkout at that moment is fatal. We kept the purchase flow tight and the account section clear, so a traveller can always see what they bought and how much data is left.
Top-ups were the feature we made sure not to bury. The whole promise of an eSIM falls apart if running low on data means starting over. In Seyyah, topping up is a first-class action — a returning traveller can refill in seconds without rebuying a plan.
The result is a travel-friendly app that does one job well: keep you connected wherever you land, without the roaming charges or the SIM-swap dance. It's a good reminder that a 'simple' consumer app often hides a lot of integration work — and that the craft is in making none of that show.
Want something like this?
This is a real project we designed and built end to end at Bloom Cypher. See the full breakdown — scope, stack and outcome — on the case study page.