Assuming your iTunes password is not 1234, the birthday of your spouse or the name of your dog (which all would be bad choices), you will not be able to remember that secure combination of letters, signs and numbers. So you have to store it somewhere, and I hope you don’t have to type it in every single time.

The following describes in shortest possible form, every step that is necessary to download an app from the iTunes App Store on an iPhone or iPad:

1) Open App Store app
2) Search for the app you want and find it
3) Tap on Download, it changes to Install App
4) Modal dialogue Enter iTunes Password pops up
5) Close enter password
6) Close App Store app
7) Open 1Password app
8) Enter 1Password pass code
9) Look up account, find and tap it
10) Enter 1Password password
11) Tap and hold iTunes password until options pop up
12) Tap on copy
13) Close 1Password app
14) Open App Store app
15) Tap on download button
16) Download button changes to Install App, tap it again
16) Paste password from clipboard in modal dialogue
17) App is downloading

There has to be a better way, Apple.