Aside from don't? Haha.
My normal goto response is, unless you have a passion for fine dining, go do something that makes money, and just host dinner parties.
Realistically though, two things. A) knife skills, learn them, though google, YouTube and practice. They will be your best asset. It will take years. There is no shortcut to experience here, but there are shortcuts to mediocrity.
B) there is nothing wrong with not remembering everything. Read up on every style of cooking and each technique, so if you are rushed you will know the basics, but there is too much to remember - don't be afraid to google how to search a specific thing. Eg roasting times for different types of meat. I looked it up tonight, I don't roast that often, so I don't remember the general times for each type of meat, there is nothing wrong with double checking your memory haha.
(Bonus?) C) once you get to my level)executive chef), don't be afraid to learn or listen, I have learnt more in the past 12 months than I would have thought possible, due to meeting chef's with an amazingly different outlook on things.
Edit:
Mobile apps? Not really, there isn't a stack overflow for chef's, or any major resource center, just Google. (I am working on this with another chef :-p)