Causality by Judea Pearl, Probability by Jaynes & Elements of Information Theory by Cover.
The above will help you design trading strategies. For modelling derivatives and such, you'll have to check out books on stochastic calculus (not my thing, so can't help there).
The FT app is based on html5. Initially, they had an app, but transitioned quickly to html5. Takes a wee bit longer to load, but barely notice that anymore. The experience otherwise is pretty much the same. And for what its worth, it's the best news app on my ipad.
Meditate! You will be happier, calmer and more focused. There are many meditations out there - be promiscuous and try out as many as you can. You will then be able to figure out what works best for you.
I loved Baby Rudin! It started my complicated love affair with mathematics. The book blew my mind away with its wonderful exposition. It's the one math book that I've worked out from cover to cover. The problems are high quality as well. I have fond (and frustrating!) memories of working them out.
I have his other 2 books as well - Adult Rudin & Functional Analysis. Sadly, I never really got into those (as my mathematical interests diverged somewhat from Analysis).
The only other book that I've read that comes close to Baby Rudin's exposition is Gamelin's Topology - an underrated classic.
The above will help you design trading strategies. For modelling derivatives and such, you'll have to check out books on stochastic calculus (not my thing, so can't help there).