Is it permissible to use the "Kik" application, which allows for recording short video clips, to disseminate advice and remind subscribers of Allah, knowing that most of its uses are for insults and unlawful matters?

There is no harm in denouncing evil, for Al-Ghazali stated that "Enjoining good and forbidding evil is the greatest pillar of the religion, and it is the important matter for which Allah sent all the prophets. If its practice were to be abandoned and its knowledge and action neglected, prophethood would cease, religion would decline, apathy would become widespread, misguidance would spread, ignorance would prevail, corruption would escalate, the rift would widen, lands would be ruined, and people would perish, yet they would not realize their destruction until the Day of Mutual Calling [Day of Judgment]."