अष्टक
Ashtak — Eight-verse stotras
An अष्टक is a stotra of eight verses — short enough to learn by heart in a few sittings, long enough to say something complete. That length is the whole point: a chalisa is a reading, an ashtak is something you carry. These are the ones we have, grouped by whom they are addressed to.
शिव · Shiva
Both are sung on Mondays and through Shravan. Lingashtakam is the shorter and easier of the two; Rudrashtakam is the one Tulsidas set in the Ramcharitmanas.
देवी व लक्ष्मी · Devi & Lakshmi
Mahalakshmi Ashtakam is the Diwali puja recitation and the quickest here to learn.
हनुमान · Hanuman
The eight-verse petition for one specific difficulty, rather than the daily reading the Chalisa is.
दत्त संप्रदाय · Datta sampraday
The अष्टक संग्रह comes from a family's handwritten notebook and we could find no other source carrying these texts — printed or online.