Add an option within Picard to check for program updates automatically (during Picard start-up?) or manually from a button with the configuration option and/or from the Help pull down menu.
Manually initiated check should display update availability status (e.g.: "No update available" or "An update is available. Current version: i.jj.kk (Your version: x.yy.zz)"), while an automatically initiated check should only display a notice if an update is available. If an update is available, the notice should also display a download link.
If an error is encountered during the check (e.g.: no network connection), it should display an error message if the check was initiated manually, otherwise it should remain silent.
Perhaps Picard can get the current release information by parsing the version information from one of the build files or the release list on GitHub, so as not to create any additional administrative updating work.