Snapchat is to allow users to change their username for the first time, with one change a year allowed for those on the social media platform. The app said the ability to alter a username had been one of the most requested features from its community. Snapchat said users would be able to change their in-app username once a year to any unclaimed handle that has not been used in the past. It said it hoped it would be an important tool for trans and non-binary users, as well as those who have changed the way they use the app since it launched in 2011. The feature will be available to all Snapchat…