For now, I just add RSI and MACD signals(that are the main signals that I am using for trading) and maybe MACD can be updated to work in multiple ways. If anyone has some suggestions I am open 
As all the technical indicators are working on multiple parameters, I am sure that you need to keep adjusting the parameters of RSI and MACD to keep your signal effective against different market fluctuations which is the reason, no such app is consistent and not becoming famous after years of existing. All exchanges are offering almost all technical indicators for every trading pair hence I guess I may not need to go for any app in my mobile as I do trade on big screens only.Maybe someone's trading habits are different, if you only need a big screen or a decent computer to trade then you don't need a smartphone screen to display trading indicators. But for some people using crypto indicator apps for mobile will be very important to monitor market prices and show some important notifications all the time.
The application that I use on a daily basis on my smartphone is usually the Tradingview application, and it is a very complete application in my opinion. if you subscribe to premium there will be many indicators that can be used.