[oreally]

I do this, but no apps, just a plain old google sheet. I sometimes miss several days due to forgetfulness and neglect, and have to recall what I did.

It's also a great way to estimate how long projects take - pretty much thanks to past data. And you can use the data to tell how productive a company is - I had one whose project iteration times are a full 50x longer than what it took to do it yourself.