Hello! I am not sure about free certifications. But I have learned a few things through here: http://howilearnedtocode.instapage.com/

They provide you with an actual certificate that has a record number and can be used for professional employment references (many take them for that) I took iOS Swift and Python. Great courses!

If is web based or app this is probably a great choice because you will spend up to 30 days learning the basics, but enough for example to build an Instagram app like for iOS... or learn other programming languages in a month. When I first developed my first app, I looked for an affordable team to join or hire. It took me about 4 months to find one that was good enough and had to hire (great programmers know they are in demand) and then another 4 months or so to develop. Now, that I know how to code, I know that those 8 months or so could have been better used me learning than paying someone, also the development doesn't have to take so long - but most charge by the hour.