I like "Noble Paths", which is a standard goal setting app refurbished for setting goals related to the 8fold path. So maybe you set a goal to really focus on Right Speech for a week, and make daily progress reports about your efforts.
I use a PDF reader that has all of the dhamma material in PDF that I've collected.
Bhikkhu P. A. Payutto has a few books available in App format, which are handy references.
"As I am, so are others;
as others are, so am I."
Having thus identified self and others,
harm no one nor have them harmed.
Sutta Nipāta 3.710