Today (May 16th) MyTrails is AppGratis‘ free app of the day, so installing MyTrails for the first time with the AppGratis application will activate MyTrails Pro for one year (MyTrails has to be run at least once during the promo period).
This will work only for new users, so what about faithful existing users, or users in countries that App of the Day does not cover? You can use the following trick:
simulate referrer appgratis hidden option to activate the promo (make sure to enter that string exactly: no extra spaces, no capitalization, etc.)
You have to do this before the promo ends (late on May 16th).
If you have already used another similar promo for MyTrails, please note they can’t be combined (even if MyTrails accepts the new promo code).
Update: the promo has been extended until May 25th to give users who were unable to activate it to do so.