Where the prices come from

The path

The ticker never talks to CoinGecko itself. It asks CryptoTicr’s own server, which fetches the data from CoinGecko and serves every ticker from one up-to-date copy, so a hiccup at CoinGecko leaves the last good answer standing rather than an empty screen. The settings page carries the Powered by: CoinGecko mark in its footer for this reason.

US dollars

Every price, market cap and volume is in US dollars, with a $ in front. The ticker has no other currency; see Can it show prices in another currency?.