If you're reading this you've already missed the January 2016 sweatshirt Salesforce offered for earning five badges on Trailhead (https://developer.salesforce.com/trailhead/en), but there are still plenty of folks willing to turn you into a mobile advertising platform.
You will be asked for personal information, a social media connection and maybe even some of your time.
NewRelic http://newrelic.com/lp/datanerd
Just sign up
MuleSoft http://champions.mulesoft.com/
Complete an hour or two's worth tasks: reading, commenting, LinkedIn connection, Twitter following, etc. After a week you'll get a link to redeem your t-shirt: I had to turn of Ghostery and uBlock Origin to complete the redemption process.
CircleCI http://blog.circleci.com/new-stickers-and-circleci-tee-shirts/
Just sign up
SmartBear http://www2.smartbear.com/Yovia-Social-TShirt-Campaign_Yovia-Social-LP.html
Download LoadComplete
5nerdssoftware: http://5nerdssoftware.com/so-you-want-a-free-shirt/
Facebook like
Mixpanel https://mixpanel.com/tshirt
Sign up, be inactive for a week (not sure if this is necessary, but I didn't get an email about the shirt until being inactive after signup), then instrument your application with Mixpanel. Or just go to your console:
m = Mixpanel::Tracker.new '<your_product_token>'
m.people.set('1', {'email':'first.last@gmail.com'})
m.track('1', 'first event')
Amazon https://developer.amazon.com/public/solutions/alexa/alexa-skills-kit/content/alexa-developer-skill-promotionPublish an Alexa skill before March 31, 2016
Rollout https://blog.rollout.io/2015/12/try-rollout-get-a-free-tshirt/
contact information
Wistia http://wistia.com/shirts
contact information
JIRA Service Desk https://www.atlassian.com/software/jira/service-desk
You have to set up an account and do some things in said account
Rollbar https://rollbar.com
Create a free account and then wait a while (2+ months?) before you instrument an application. I got an email saying that if I instrumented an application with Rollbar they'd send me a shirt for free.
DataDog https://www.datadoghq.com/ts/nagios/
I started a free trial and continue to have free monitoring on a non-production PostgreSQL instance.
On hold
These free shirt offers seem to be over/on hold:
WhenIWork http://wheniwork.com/free-shirt
Codeship https://codeship.com/swag
