The 1.0 version of InputSwitcher for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The bundle id for this application is InputSwitcher.
The following version: 1.0 is the most frequently downloaded one by the program users. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The actual developer of this free Mac application is Satoshi Nakagawa.
From the developer:
InputSwitcher is an utility software to save the input source state of each application on Leopard. It doesn't work on Tiger or below.
Then start InputSwitcher.app and restart other applications, it will be working. You can see it saves the input source states as pushing cmd space or cmd option space on each application and move the focus to the other applications.