Abu Hurairah (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "Whoever sits in a gathering and indulges in useless talk and before getting up supplicates: 'Subhanaka Allahumma wa bihamdika, ash-hadu an la ilaha illa Anta, astaghfiruka wa atubu ilaika (O Allah, You are free from every imperfection; praise be to You. I testify that there is no true god except You; I ask Your Pardon and turn to You in repentance),' he will be forgiven for (the sins he may have intentionally or unintentionally committed) in that assembly."[At-Tirmidhi].
App reference: Book 5, Hadith 19
Arabic/English book reference: Book 5, Hadith 832