One of the new additions in this latest update is the video streaming option which lets users watch videos directly on the app without having to download. The streaming window will feature a progressive bar as well as a light gray strip which will let you know how much of the video is currently cached. The streaming feature will however only work on videos uploaded on the version 4.8 or later.
Another newly added feature is the Auto-Night Mode which when enabled will make the app automatically switch to a darker theme once it's night time or in a low light condition. You also have the option to select the dark theme you will like to use from the several ones available on telegram. To setup the Auto-Night Mode, just go to Auto-Night Mode by heading over to Settings >> Theme >> Auto-Night Mode.
The third new feature is the telegram login which will give External Websites the option to add a special telegram login feature for quick authentication, this will work in a similar way as the Facebook widget. When using it for the first time, you will be asked to input your phone number so as to receive a telegram authentication message. Doing this will give you the benefit of 2 step login verification on all website with the new feature.
The latest Telegram version 4.8 is currently available on the Google Play store for Android users and it's expected to roll out to iOS users pretty soon.