We talk a lot about how encrypting your files is ethically and professionally critical, but the truth is that sometimes it is much easier to trade convenience for safety. Often, it is so much easier to bring your iPad to a meeting or a coffee shop rather than lugging around a laptop.
Insight Notes aims to make using your iPad a bit more secure by locally encrypting your notes and allowing (if you want to pay the extra $14.99 for cloud storage) you to back them up to a secure, encrypted server. It was designed for healthcare professionals to take notes in the field, but could work for attorneys as well.
Besides being encrypted, Insight Notes looks fancy. You can type, draw, or scan notes on the iPad and it will organize the records by date and client. It bulk exports notes (and keeps them encrypted while it does) and will put your note on letterhead with signature and contact info if you like.
Insight Notes is $9.99 in the App store. (Sorry, no Android version.)