Questioner

Questioner allows you to create custom question and answer XML documents (or use preexisting ones), to quiz yourself on any topic of your choice. Progress through the questions in order or at random to mix it up for yourself.

Simply load up an xml, and swipe between questions, pressing and holding the answer area to see the answer when you are ready. Questioner can also be opened by clicking a questioner xml file from a file manager.

For some sample question xml files, follow this link: https://github.com/aldendino/Questioner/tree/master/input
For the desktop version built in java, follow this link: https://github.com/aldendino/Questioner

Note: External Storage Read Permissions are necessary for reading the xml files from the directory of your phone, and are used in no way other than that. If you do not see your device's internal storage, you may need to enable "Display advanced devices" in the file chooser settings.