macOS Catalina (10.15) and later versions of macOS will not support 32-bit apps and other software. Before upgrading to Catalina, you can run 32BitAppCheck to get a savable, searchable list of these 32 bit software. To collect the information, just click the Collect Info button, and be patient for a couple of minutes.
Information then collected in the app's window begins with a list of 32-bit applications, followed by 32-bit preference panes found in System preferences. Then, you will see 32-bit system extensions, and 32-bit system frameworks. These software will include both Apple and 3rd-party software.
You can then edit the information, changing fonts, and adding notes. Click Save to save the information in an RTF file. The most recent information with you edits is also saved within the app.
To download a zip file containing 32BitAppCheck, click here.