Not modal; not having separate modes in which user input has different effects.(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "modeless" in a sentence
"I believe in modeless software, search should always be search, nothing more nothing less."
"In the new BBEdit, the search windows for both Find and Multi-File Search are modeless, meaning you can move freely back and forth between an open document and the search window, without closing the latter."
"For when you are at the computer, a good note-taking program should be “pop-up” or “modeless,” which means that you can immediately call it up, usually with one keystroke, without switching away from the Web page you are viewing or the document you are working on."