I've always used Snipit with Win7 but don't know anything about Apple products since the day the ipods came out and we spent thousands of dollars on them only to find out they are locked proprietary where you have to pay ransom $1 per song even if you already own the mp3 files. So fuck Steve Jobs and everything he ever had anything do to with. That company makes money by unfair and deceptive trade practices. Fuck them. Don't ask me how to use a Mac unless you want instructions on how to throw it in the trash. In that case, open waste receptacle, deposit Apple product, and close waste receptacle.
Off Topic:
Not to side track thread, but agree about Apple and their "captive marketing". I transitioned to all Google a few months ago. Nexus 5 & 7, gmail, google calendar, google drive, google play, google play music, docs, chrome. All devices are synced flawlessly: data, contacts, tasks, events, music, video, etc...
[even my MS office is becoming obsolete, I only use "outlook" now as an archive by using IMAP to combine and pull messages from multiple email address's created over the years]
The Google Play "store" has all the apps I need. I will never go back to Apple. I detested iTunes, and Google has solved that for me...
I also have a drawer full of iPhones, iPods etc... My son asked if he could have one of my unused iPhones. My reply, "we will never install that hideous iTunes again", so I ordered him a nexus 5 instead.
On Topic:
Regarding screen capture: I really like
http://www.faststone.org/FSCaptureDetail.htm
Not free ~ $20/lifetime, but, extremely light, clean.
I never experienced any conflicts using FastStone, but I have had issues with Jing/snagit in the past.
Free isn't always the best choice.