My go-to photo editor on phone and iPad is the wonderful and surprisingly adept Snapseed app which is available for free on android and Apple devices. If you have not tried it out then give it a whirl and see for yourself what the fuss is all about.
I took a portrait of the plastic model head earlier today and then converted it to jpg via RawTherapee on Linux, transferred it to my Apple phone, played around a bit with Snapseed and then transferred them back to the computer and resized in the free GIMP photo editor.
I have posted a random selection of various versions of the portrait below for you to peruse.
Personally I am impressed by the quality of the output from Snapseed and also that it is so wonderfully versatile & handy to use to get some interesting looks. It isn't for everyone, but it's free and it just works.
|The original portrait photograph|
Six examples of the Snapseed treatment:
|Black and White with film grain|
|Noir with added frame|