You can use Binance, they are doing the work automatically, so you do not need to wait for the price to rise to a certain level, but by using some software orders, you can buy and sell without having to be in front of the computer screen.
What do you mean doing the work automatically? Binance is just an exchange, it won't help you to set your strategy, or even pump the price for you. It's a 'good' exchange if you do day-trading due to it's high volume and things like that, but they're not offering any help for you. The buy/sell without being in front of your computer, as you said, is possible in other exchange as long as the bot that you use supports its API.