Most exchanges do not have there own trading app in the app store, but fortunately there are some interesting apps in the App Store which can help you trade with the API keys of your exchange. 

Trading apps can help you trade smart and act fast on price changes, see below the top 5 best trading apps for iPhone and iPad

#1 Trading Coins - BTC Exchange

Downloadlink App Store

Pros:

• Clean and easy user interface
• Smart trading options
• Price alerts for all altcoins
• Clean portfolio with export to CSV
• Passcode lock

Cons:

• Only working with Bittrex API Keys
• No iPad landscape mode

#2 CryptoTrader - Bitcoin, Ethereum Real-time Chart

Downloadlink App Store

Pros:

• Great charts
• Historical Price Data

Cons:

• Only a handful altcoins
• No option to trade
• No price alerts
• Not all currencies supported

#3 Coinbase - Buy Bitcoin & more

Downloadlink App Store

Pros:

• Original Coinbase app
• Connected with your coinbase account

Cons:

• No exchange, only swapping
• High Fees
• Only a handful altcoins

#4 Trading 212

Downloadlink App Store

Pros:

• Easy to use

Cons: 

• High fees
• Only a handful altcoins
• Based on Forex Trading

#5 Polo Exchange

Downloadlink App Store

Pros:

• Candle Charts

Cons: 

• Difficult UI
• Only works with Poloniex
• Bad design

These are my top 5 Trading Apps for cryptocurrency. If you have any other apps that are worth using please let us know in the comments. Thanks!