In case you want to use the Legacy Firmware 3 app, but it's unavailable to you, you can try using this trick to quickly access the interface that the app uses.
Keep in mind that this only works on browsers that allow you to create shortcuts on your home screen, by default Chrome and Safari will allow you to do this.
Step 1: Open old.handyfeeling.com on your browser, in this example we are using Chrome.
Step 2: Open the settings and scroll down until you find the options "Add to Home Screen" and select it.
Step 3: Once you select it, you will be prompted with an install pop-up window. You can select Install here, this won't be an actual app but it will open a browser window with the site in question.
Step 4: Wait for the installing to complete.
Step 5: Go to your home screen and check the app's function, if all was done correctly you now have a "app" on your device.