When you sign-into the app, the version number can be seen offest in the top right by the logo at the top of the page.
There is no need to worry about the latest version or if you have it running since you never have to install any software on either the sender device or the receiver device it makes it much easier for everyone.
The version number we have is there for our purposes should there be an incompatability between device and browser that we have detected to let you know that you may have to do something to avoid being disappointed.
No install of software, fully end-to-end encrypted, secure delivery from one device to another, we never compress any data, we never share any data, we just deliver data that we are given as quickly as possible to the receiver.