I work at a small, non-tech family business. I am the default IT guy, and I have made a ton of internal tools for us. Most of these are either only useful to us or would be hard to make universally for others. However, I have turned a few into B2B web apps that have good traffic and earn a couple hundred each month with virtually no effort or optimization. And the opportunity exists to turn these into more robust SAAS offerings or do contract work, but that would be less passive.
Not everyone is in this position, so it is a very interesting conundrum. If you know anyone that works for or owns a small business or works as a professional in a specific field, ask them about the tools they already use and what tools they would like to have. Tell them to let you know the next time they are facing a problem that they know could be done better/easier/faster through a tool or app. If you can make something that will help them, perhaps it will help others. Custom forms, data collection, etc.
Not everyone is in this position, so it is a very interesting conundrum. If you know anyone that works for or owns a small business or works as a professional in a specific field, ask them about the tools they already use and what tools they would like to have. Tell them to let you know the next time they are facing a problem that they know could be done better/easier/faster through a tool or app. If you can make something that will help them, perhaps it will help others. Custom forms, data collection, etc.