Seriously, I'm very surprised hearing that you are not familiar with so many applications that can offer you the best features to edit your pictures and tune it up to your taste before uploading it to any social media sites of your choosing. If my memory serves me correctly, back in the days it's Picmix that was very popular and used by so many people but today, there are countless pictures editing softwares and applications.
There are so many examples of such applications and they include the following ; photo studio, Photo editor, Pixlr, Adobe Photoshop, SnapPic Collage, Cartoon photo editor, Photo collage, PhotoGrid, Selfie Photo editor, Cut paste photo editor, PIP camera, S Photo editor, Photo effects, Beauty Camera photo editor etc.
All these applications are available on Google Play store.