21 CFR § 801.50 - Labeling requirements for stand-alone software.
(a) Stand-alone software that is not distributed in packaged form (e.g., when downloaded from a Web site) is deemed to meet the UDI labeling requirements of this subpart if it complies with the requirements of paragraph (b) of this section and conveys the version number in its production identifier.
(b) Regardless of whether it is or is not distributed in packaged form, stand-alone software regulated as a medical device must provide its unique device identifier through either or both of the following:
(1) An easily readable plain-text statement displayed whenever the software is started;
(2) An easily readable plain-text statement displayed through a menu command (e.g., an “About * * *” command).
(c) Stand-alone software that is distributed in both packaged form and in a form that is not packaged (e.g., when downloaded from a Web site) may be identified with the same device identifier.