Hi, the source is not made public to demotivate to make a copy or spin offs of the app or to use it in ways that would not benefit the users.

Conventional mining on a pc is done based on proof of work, virtual mobile mining is based on proof of time, we count the time the user is engaged with the app.

it's somewhat similar to Electroneum and Phoneum there mobile apps, but the difference is that we adapted the mobile miner concept for the Steem blockchain, with Steem related features.