Here you are, finally! I (was about to go/ would go home.

Sorry I'm late. I (would call/wasabout to call) you, but ... well, to be honest, I just forgot!

I thought so. You’re so forgetful! And yesterday you promised you (wouldn't have been/ wouldn't be) late this time!

I actually downloaded an app on my phone last week that said it (would have improved/ would improve) my memory within five days.

Well, I used it on the first day, and it seemed quite good. Then I (was/were) supposed to use it every day for ten minutes.