I use a pocket-sized Sennheiser MKE 200. It was recommended by a friend who’s a serious recordist when I asked how to up my game without a dedicated sound rig. It does make a big difference for fainter sounds (contrary to the eBird advice, https://support.ebird.org/en/support/solutions/articles/48001064305-smartphone-recording-tips). The fluffy cover is good for light winds, though it won’t completely eliminate noise from strong ones. And I don’t find the mic to be particularly directional.
For editing I use Ocenaudio, which is free, user-friendly and full-featured. I haven’t compared to any others.