WalkonwebWalkonweb
LIVE PRODUCT CASE STUDY

Building Zaplert:
Crypto alerts people can trust

Zaplert is Walkonweb's live crypto price alert product. Users set clear rules—price targets, percentage moves, ranges, and watchlist updates—then get mobile push notifications when live market data matches those rules.

View Zaplert product page

Binance spot

Market data

Android & iOS

Clients

Expo / React Native

Mobile stack

Live product

Status

01. The Product Challenge

Reliable alerts without drowning users in noise

Crypto markets move continuously. Traders need a simple way to watch specific levels and percentage moves on phones—without polling charts all day or getting spammy duplicate pushes when price oscillates around a threshold.

  • Stream live prices from exchange market data (Binance spot) into the product backend.
  • Evaluate user rules such as price above/below, % increase/decrease, price range, and watchlist updates.
  • Deliver push notifications to Android and iOS with account controls for privacy and deletion.

02. What we shipped

A focused mobile product stack

The build prioritizes what users need day to day—not an over-marketed platform story.

Mobile client

React Native + Expo

Auth, live markets, favorites, alert creation, history, and push token sync in one cross-platform app.

Market data

Binance REST + WebSocket

Live spot listings, movers, and coin detail with TradingView charts for context before setting alerts.

Alert engine

API-backed rule evaluation

Server-side alert CRUD and evaluation for price, percentage, range, and watchlist conditions.

Notifications

Expo Notifications / FCM

Push delivery with alert history and delivery logs so users can verify what fired.

03. Product principles

Honest scope, production discipline

1. Rule-based alerts—not AI hype

Zaplert does what it claims: evaluate explicit user rules against live prices. No fabricated “AI market insights” layer. That clarity keeps trust high for both users and store reviewers.

2. Store-ready account controls

Privacy policy and a public data-deletion flow ship with the product so Android / iOS compliance is not an afterthought.

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Running Zaplert in production keeps Walkonweb honest about delivery—mobile clients, APIs, notifications, and compliance included.

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