As noted in my original question, my account is a POP/IMAP account: "I would have tried Outlook for the Android, but that seems to be written to work only with Exchange or other non-POP/IMAP accounts, and my account is a POP account".
That is, it is not an Exchange or Office365 account that has built-in automatic synchronization; I have to synchronize with my computer. This rules out four of the five options at the link you provide, leaving only the product that requires a purchase:
#1 MS Outlook app: it synchronizes with an Exchange online account, not an Outlook file. That is, it works only if it can connect directly to the mail server where the contacts reside, but the nature of IMAP/POP does not have contacts reside in the online account/database, but within an Outlook .pst file on the computer only, where it presumably requires a MAPI connection to synchronize via WiFi, Bluetooth, or USB.
#2 GMail app: "Make sure to add your Outlook account via Exchange and Office 365. Note: Do not select Outlook, Hotmail, and Live since it uses POP and IMAP which doesn’t support calendar and contacts syncing." But my account is a POP/IMAP account, so I am using the GMail app to retrieve email, but as in #1, my contacts do not reside in the mail account--only in the Outlook .pst file on my computer.
#3 Outlook Android App: not advertised, but it is exactly the same as #1 & 2: it synchronizes with an account in which the contacts do not reside on the computer, but within the online Exchange database, where they are accessible directly by multiple devices. My contacts reside only on my computer within an Outlook .pst data file.
#4 Calendar app: does not synchronize contacts.
#5 CompanionLink/DejaOffice: I have to decide if I want to swallow the $50 cost.
