If you're interested in cutting edge Construct features try the Beta releases. These releases should not be used unless you are willing to tolerate some bugs.
Hotfix for issue in r42
Preview now runs on preview.construct.net
Built-in dark theme, Xbox Live updates, bug fixes
'Pick last created', safe mode, memory optimisation & more bug fixes
Re-land the architectural change originally made for r38
Themes support, usability improvements, architectural changes
Back button support on mobile, popup remote preview, more bug fixes
Access codes, split Cordova exporter, and more.
More bug fixes and some usability tweaks