If you haven't tried birding, try it. You'll like it. It's like collecting Pokemon, but IRL.
I've used Merlin for years and it works great most of the time. Agree with others that it's a great example of something we should all have on the tiny computers in our pockets.
Until this thread I didn't realise it did photo ID! I took a photo of a black redstart last year and at the time was able to identify it via photos uploaded to social media. But I just tried the app and it got it straight away. It also added it as a new 'lifer' because I hadn't previously logged it via audio ID. Cool!