He was smart to abandon his minimal time tracker, minimal metronome and jobs website.
BTW: he didn't get 5 users for minimal time tracker, he got 5 people who signed up for a mailing list based on screenshots of non-existing product.
Even smarter would be to not do such projects in the first place.
With jobs websites you need a giant, unfair advantage over all other job websites.
Metronome and minimal time tracker are both vitamins, not pain killers. They don't solve a painful problem that people are obviously willing to pay for.
They are also extremely competitive.
The only idea that was somewhat viable was time tracker, but only if he managed to stand out from all the other time trackers and masterfully execute both the product and marketing.
There is no recipe for a successful projects but there are plenty of giant red flags that you should notice and avoid.
High competition is a red flag. Low value to potential users is a red flag.