i use all exchanges only in browser.
i do not understand the hype to have a dedicated "app" for each trivial service, which i can visit as a website.
It's not that it's not good or issue about security, but I am more comfortable trading my coins with my desktop or laptop, I can have a good look on the chart than when I'm looking it on my phone, I can easily shit my tab when I am on my desktop than using my phone, I cannot speak for other users, when it comes to trading it's everyone for himself, where he is comfortable trading.