LanSend can look for new versions on its own and download them in the background. You decide how that works on the Updates page in Preferences, and you can run a check yourself whenever you want.

There are two ways to start a check by hand:
The Updates page also shows Current version, Last check, and Next check, so you can see which build you are on and when the next automatic check is due.
On the Updates page, Update mode has four settings:
Check frequency controls the automatic check: On startup, Daily, Weekly, or Monthly. The default is Weekly. This setting has no effect in Manual mode, which never checks on its own.
Every download is verified for authenticity and integrity before it installs, so you can let the update run without inspecting the file yourself.