I did search for this before posting, if I missed something, my sincere apologies:
Due to poor and diminishing motor control, I am looking for a screenshot app for Lollipop and up that allows one-button capture without root access. I can't master the standard 2-button press on my Huawei Mediapad M2, and the reviews of screenshot apps on the Play Store are all over the place. I'm happy to buy an app if it's well recommended.