Tabtrader is one of the best apps I've ever used. Its price is updated at the right time and not only I use, pro traders also use it for many purposes. There are many functions of calculating profit and viewing orders at different large exchanges. Besides, you can set up price alerts, if the price falls to an alarming level, you will be notified immediately and do not miss the opportunity.
Alternatively, you can use blockfolio. It also supports viewing prices of various coins and tokens, it also has a news page to read, which is very convenient.