[somecallitblues]

From my own experience: do not build a product until you find someone to pay for it. Unless you are really cashed up but even then you need a customer to drive it.

Take everything you can at the beginning and occasionally charge in beer for small things that took 20 minutes. Some of my biggest jobs came from some of those customers.

If you get along well with your colleague then partner up. You'll help each other out when going gets hard.

Don't be afraid to make drastic changes, like abandoning a product that doesn't sell.

Creative agencies without inhouse devs are your bread and butter until you get that recurring revenue from your products.

Expect to productize the most random stuff you would never think off.

Excel is your biggest competitor.

Go for it! Good luck!