There are three different ways in which you could include a powerpoint presentation in your ePoster/Stack:
1. As a File (PowerPoint)
The first would be to add a File tile from the Tile Library and then add the powerpoint file in the Add File box that appears to the right. If you watch video 3 (http://support.ltb.io/faq/) between time 10:20 and 11:05 then you will see how we use the File tile to add a PDF file to an ePoster. To add a powerpoint file you would follow the same steps, but upload your powerpoint file instead. However, if you do it this way then your ePoster viewer will have to have a powerpoint program/viewer installed on their phone/tablet if they want to view your presentation.
2. As a File (PDF)
The second way is very similar to the first, but in this case you could save your powerpoint file to a PDF first and upload the PDF file into your ePoster (using the File tile as described above). The advantage of this approach is that Learning Toolbox has a built in PDF viewer, so your ePoster viewers will be able to view your presentation within the Learning Toolbox app without installing any other special software.
3. As Online Content (Using Slideshare)
The final approach you could use is to first upload your powerpoint to slideshare https://www.slideshare.net/ This will then create a slideshare version of your powerpoint that is viewable online (and within the Learning Toolbox app). Within Learning Toolbox you can then add an Online Content tile to your ePoster and add in the url link to your slideshare presentation. Doing it this way will mean that people can view your presentation within Learning Toolbox itself, they will not need to have any other special software installed. If you watch video 3 (http://support.ltb.io/faq/) between time 9:08 and 10:20 then you will see how we use the Online Content tile to add a Youtube video. To add a slideshare presentation you would follow the same steps, but paste in the url of your slideshare presentation (instead of the url to a youtube video).