Where can we download the presentation?
The presentation is now available from this link.
Which IDE is this?
The IDE I use is called Brackets.
Could you provide links to tutorials in relation to developing apps with ArcGIS API code?
Is there any licence option between 5 user licence and 50 user licence yet?
Currently named user licences only come in packs of 5 or 50 for ArcGIS Online. However, you can purchase 2 x 5 named user licences if necessary.
3D support in JS by ESRI, wherein we can create web apps from 3D Scene services also even on Mobile device using webGL or similar technology.
Coding in relation to widgets for ArcGIS Online apps.
I assume you are speaking about Web AppBuilder widgets. There are some very good videos relating to customising and extending Web AppBuilder for ArcGIS widgets available from this link. We will consider this topic for a future webinar.
Some useful resources can be found below: