For the web app, your learners will need around 1 MB of data to load the web app and around 1-3 MB per course taken (depending on the length of the course and the number of images you include). These figures will be significantly less the second time they load the web app as the main assets (images, sounds etc.) should be cached in their browser.
For the Android app your learners will need around 30 MB of data to download the app and 1-3 MB to save a course for offline use.
Using the web app
The amount of data used to take a course is primarily dependent on the number of images and the use of videos. On average we find that a course with 2 modules (that includes lots of images but no videos) uses around 1MB of data. As standard we compress all images so the maximum size of any image should be around 100KB. The images will also be cached in your learners' browser so once they've downloaded an image they won't have to re-download it. This means they can go back over lessons and quizzes and only use a very small amount of additional data.
Using the Android app
Downloading the Android app requires around 30MB of data. We bundle all of the assets required to run the app (images, sounds, animations etc.) inside the app install. This means that one your learners have downloaded and logged into the Android app they can use it even when offline.
We do not automatically save all courses for offline use as we want learners to be in control of the data they're spending. If they press on a course then it will be downloaded and saved to their device, they can also select which courses to download by pressing on the "Save Offline" button. Downloading the course requires downloading the text and images associated with that course. As above, this should be around 1MB of data for a course with 2 modules (that includes lots of images but no videos).