There are lot of EA available in the market. Some of them are good some of them are bad. Some EA provider offers I free and some charge for it. So, be careful when you buy some. Lot of scam provider are waiting to scam you. Some EA will suitable for your trading style. So, test it in demo account first before using it in real account. As for me my broker Eurotrader support any kind of EA in their mt4 and mt5 platform.