Investing Apps?

Does anyone know or use any investing apps? Aside from BTC/Ether , I wanted to invest in something a bit safer. I'm not the most knowledgeable person when it comes to this so I decided to go with an app that would do it for me. I looked at Acorns / Betterment. Would seem Acorns have a good and clean app but their fees are a bit high , so I'm probably going to go with Betterment, anyone have experience with these kinda things?

 

robinhood is popular, betterment > acorns from what i've heard. can also just download whichever brokerage's app has the lowest fees and buy an index fund or something