Yes it does show you what is available right now, and also a timer so you know how long it’s got to go. Personally, that’s exactly what I want to know.. what I can get right now. But make sure your phone’s time is set correctly, otherwise you might miss something.
The map also allows you to filter, so you can choose to filter out pokemon that you don’t want to show up. I do this for all the really common ones that I don’t particularly care about – Caterpie, Weedle, Pidgie, Zubat, Kakuna, Rattata, Psyduck, Tentacool, Magikarp. That way, the map isn’t so clogged up and it shows clearer, the ones that I actually want to go out and get, without all the rubbish. Sire I’ll encounter those on the way, but if I have to use my phone screen to view the map, I want to have the best view possible.
It also allows notifications (on-screen only, and the icon bounces on the map) of when certain Pokemon spawn, which you also specify.