Application (or app): A program that reads and displays a PDF or ChordPro file
Console: A functionality of ForScore and OnSong that allows you to edit your song files in a browser window from your PC.
ChordPro: A markup language that identifies the differences between chords, choruses, bridges, etc to allow a program to display a lead sheet correctly on screen.
Filk: The folk music community of science-fiction and fantasy fandom. Yes, I am a part of that fandom.
Markup language: a system for annotating a document in a way that is syntactically distinguishable from the text, meaning when the document is processed for display, the markup language is not shown, and is only used to format the text. HTML and ChordPro are markup languages.
PDF: a file format developed by Adobe in the 1990s to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. PDF was standardized as ISO 32000 in 2008, and no longer requires any royalties for its implementation.
Platform: the hardware/OS combination that is used. Here, we are generally referring to either the Android or iOS platforms.