This app was mentioned in 10 comments, with an average of 2.30 upvotes
Screenshot utility - markup your screenshots with arrows, rectangles, blur parts, all in compact very simple to use app
I was doing for wife research on these apps and settled on installing above, it's very simple to use, not bloated without tons of unnecessary features and not coming from China (ehm Screen master)
Andmade share - old but still works fine on Oreo, customize completely your share menu if you are sick of stock clutter
Kii 2 keyboard - if your are looking for swiping keyboard alternative to Gboard and Swype this one seem on par with Swype in accuracy and vocabulary by my testing for many days, not updated anymore though
Shortcutter - customize quick tiles, personally I just used it to add Heads up notifications tile on Oreo, disable them globally and uninstall, but I guess you could just it for more
Wow. She's dumb. Here this will help with your screenshots
tested bunch for wife, this is simple and powerful
stay away especially from screenmaster Chinese spyware recommended ITT
OT but if you markup screenshots often I recommend installing Screenshot utility, you could just blur the account/phone, just mentioning it because few days ago I was doing research on these apps for wife