JSON with price AND daily change? May be someone could point me towards a public API with Bitcoin price AND 24h change? Like $7'602 +2.3%?

All APIs I've found (like coindesk's) only contain price, not change :(
You can calculate the change yourself. The coinbase API (not a recommendation, just an example) has and endpoint for 24-hour stats (https://api.pro.coinbase.com/products/BTC-USD/stats)

{
open: "7674.24000000",
high: "7810.99000000",
low: "7490.00000000",
volume: "14477.94427039",
last: "7694.56000000",
volume_30day: "479763.13996598"
}


Last price minus the open price equals the 24 hour gain. Divide the gain by the open to get the decimal percentage.