Apart from being a versatile Auto Save Notepad, it offers the following features over and above the free version.
1) Unlimited notepad slots
2) Import / Export notes selectively
3) Search within and across notes
4) Send text from any external app
5) Lots of configuration options
6) Full screen view of note and list
Please check the box for – ‘Allow installs from other sources than the Play Store’ in your settings